Dna-pk inhibitors

ABSTRACT

A compound of formula I: 
     
       
         
         
             
             
         
       
     
     and isomers, salts, solvates, chemically protected forms, and prodrugs thereof, wherein: R 1  and R 2  are independently selected from hydrogen, an optionally substituted C 1-7  alkyl group, C 3-20  heterocyclyl group, or C 5-20  aryl group, or may together form, along with the nitrogen atom to which they are attached, an optionally substituted heterocyclic ring having from 4 to 8 ring atoms; Q is —NH—C(═O)— or —O—; Y is an optionally substituted C 1-5  alkylene group; X is selected from SR 3  or NR 4 R 5 , wherein, R 3 , or R 4  and R 5  are independently selected from hydrogen, optionally substituted C 1-7  alkyl, C 5-20  aryl, or C 3-20  heterocyclyl groups, or R 4  and R 5  may together form, along with the nitrogen atom to which they are attached, an optionally substituted heterocyclic ring having from 4 to 8 ring atoms; if Q is —O—, X is additionally selected from —C(═O)—NR 6 R 7 , wherein R 6  and R 7  are independently selected from hydrogen, optionally substituted C 1-7  alkyl, C 5-20  aryl, or C 3-20  heterocyclyl groups, or R 6  and R 7  may together form, along with the nitrogen atom to which they are attached, an optionally substituted heterocyclic ring having from 4 to 8 ring atoms; and if Q is —NH—C(═O)—, —Y—X may additionally be selected from C 1-7  alkyl.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/231,041, filed on Sep. 20, 2005, which claims the priority benefitsof U.S. Provisional Application No. 60/611,515, filed on Sep. 20, 2004,and which are both incorporated herein by reference.

The present invention relates to compounds which act as DNA-PKinhibitors, their use and synthesis.

The DNA-dependent protein kinase (DNA-PK) is a nuclear serine/threonineprotein kinase that is activated upon association with DNA. Biochemicaland genetic data have revealed this kinase to be composed of a largecatalytic subunit, termed DNA-PKcs, and a regulatory component termedKu. DNA-PK has been shown to be a crucial component of both the DNAdouble-strand break (DSB) repair machinery and the V(D)J recombinationapparatus. In addition, recent work has implicated DNA-PK components ina variety of other processes, including the modulation of chromatinstructure and telomere maintenance (Smith, G. C. M. and Jackson, S. P.,Genes and Dev. 13: 916-934 (1999)).

DNA DSBs are regarded as the most lethal lesion a cell can encounter. Tocombat the serious threats posed by DNA DSBs, eukaryotic cells haveevolved several mechanisms to mediate their repair. In highereukaryotes, the predominant of these mechanisms is DNA non-homologousend-joining (NHEJ), also known as illegitimate recombination. DNA-PKplays a key role in this pathway. Increased DNA-PK activity has beendemonstrated both in vitro and in vivo and correlates with theresistance of tumour cells IR and bifunctional alkylating agents (MullerC., et al., Blood, 92, 2213-2219 (1998), Sirzen F., et al., Eur. J.Cancer, 35, 111-116 (1999)). Therefore, increased DNA-PK activity hasbeen proposed as a cellular and tumour resistance mechanism. Hence,inhibition of DNA-PK with a small molecule inhibitor may proveefficacious in tumours where over-expression is regarded as a resistancemechanism.

It also has been previously found that the PI 3-kinase inhibitorLY294002:

is able to inhibit DNA-PK function in vitro (Izzard, R. A., et al.,Cancer Res. 59: 2581-2586 (1999)). The IC₅₀ (concentration at which 50%of enzyme activity is lost) for LY294002 towards DNA-PK is, at ˜1 μM,the same as that for PI 3-kinase. Furthermore it has been shown thatLY294002 is also able to weakly sensitise cells to the effects of IR(Rosenzweig, K. E., et al., Clin. Cancer Res. 3: 1149-1156 (1999)).

WO 03/024949 describes a number of classes of compounds useful as DNA-PKinhibitors, including 2-amino-chromen-4-ones of the general structure:

of which:

was one example. This compound exhibited an IC₅₀ of 10-12 nM and an SERof 1.3 (see below for methods).

Other examples of a DNA-PK inhibitors include1(2-hydroxy-4-morpholin-4-yl-phenyl)-ethanone (Kashishian, A., et al.,Mol. Cancer Ther, 2, 1257-1264 (2003))):

and SU11752 (Ismail, I. H., et al., Oncogene, 23, 873-882 (2004))

Given the involvement of DNA-PK in DNA repair processes, and that smallmolecule inhibitors have been shown to radio- and chemo-sensitisemammalian cells in culture, an application of specific DNA-PK inhibitorydrugs would be to act as agents that will enhance the efficacy of bothcancer chemotherapy and radiotherapy. DNA-PK inhibitors may also proveuseful in the treatment of retroviral mediated diseases. For example ithas been demonstrated that loss of DNA-PK activity severely repressesthe process of retroviral integration (Daniel R, et al., Science,284:644-7 (1999)).

The present inventors have now discovered related compounds whichexhibit similar or improved levels of DNA-PK inhibition, whilstpossessing other useful properties for use as active pharmaceuticals, inparticular improved solubility.

Accordingly, the first aspect of the invention provides a compound offormula I:

and isomers, salts, solvates, chemically protected forms, and prodrugsthereof, wherein: R¹ and R² are independently selected from hydrogen, anoptionally substituted C₁₋₇ alkyl group, C₃₋₂₀ heterocyclyl group, orC₅₋₂₀ aryl group, or may together form, along with the nitrogen atom towhich they are attached, an optionally substituted heterocyclic ringhaving from 4 to 8 ring atoms;

Q is —NH—C(═O)— or —O—;

Y is an optionally substituted C₁₋₅ alkylene group;X is selected from SR³ or NR⁴R⁵, wherein,R³, or R⁴ and R⁵ are independently selected from hydrogen, optionallysubstituted C₁₋₇ alkyl, C₅₋₂₀ aryl, or C₃₋₂₀ heterocyclyl groups, or R⁴and R⁵ may together form, along with the nitrogen atom to which they areattached, an optionally substituted heterocyclic ring having from 4 to 8ring atoms;if Q is —O—, X is additionally selected from —C(═O)—NR⁶R⁷, wherein R⁶and R⁷ are independently selected from hydrogen, optionally substitutedC₁₋₇ alkyl, C₅₋₂₀ aryl, or C₃₋₂₀ heterocyclyl groups, or R⁶ and R⁷ maytogether form, along with the nitrogen atom to which they are attached,an optionally substituted heterocyclic ring having from 4 to 8 ringatoms; andif Q is —NH—C(═O)—, —Y—X may additionally selected from C₁₋₇ alkyl.

A second aspect of the invention provides a composition comprising acompound of the first aspect and a pharmaceutically acceptable carrieror diluent.

A third aspect of the invention provides a compound of the first aspectfor use in a method of therapy.

A fourth aspect of the invention provides for the use of a compound ofthe first aspect in the preparation of a medicament for treating adisease ameliorated by the inhibition of DNA-PK.

It is preferred that the medicament of the fourth aspect selectivityinhibits the activity of DNA-PK compared to PI 3-kinase and/or ATM.Selectivity is an important issue as inhibition of other PI 3-kinasefamily members may lead to unwanted side-effects associated with theloss of function of those enzymes.

In particular, the compounds may be used in the preparation of amedicament for:

(a) use as an adjunct in cancer therapy or for potentiating tumour cellsfor treatment with ionising radiation or chemotherapeutic agents; or(b) the treatment of retroviral mediated diseases.

A further aspect of the invention provides an active compound asdescribed herein for use in a method of treatment of the human or animalbody, preferably in the form of a pharmaceutical composition.

Another aspect of the invention provides a method of inhibiting DNA-PKin vitro or in vivo, comprising contacting a cell with an effectiveamount of an active compound as described herein.

DEFINITIONS

C₁₋₇ alkyl: The term “C₁₋₇ alkyl”, as used herein, pertains to amonovalent moiety obtained by removing a hydrogen atom from a C₁₋₇hydrocarbon compound having from 1 to 7 carbon atoms, which may bealiphatic or alicyclic, or a combination thereof, and which may besaturated, partially unsaturated, or fully unsaturated.

Examples of saturated linear C₁₋₇ alkyl groups include, but are notlimited to, methyl, ethyl, n-propyl, n-butyl, and n-pentyl (amyl).

Examples of saturated branched C₁₋₇ alkyl groups include, but are notlimited to, iso-propyl, iso-butyl, sec-butyl, tert-butyl, andneo-pentyl.

Examples of saturated alicyclic C₁₋₇ alkyl groups (also referred to as“C₃₋₇ cycloalkyl” groups) include, but are not limited to, groups suchas cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl, as well assubstituted groups (e.g., groups which comprise such groups), such asmethylcyclopropyl, dimethylcyclopropyl, methylcyclobutyl,dimethylcyclobutyl, methylcyclopentyl, dimethylcyclopentyl,methylcyclohexyl, dimethylcyclohexyl, cyclopropylmethyl andcyclohexylmethyl.

Examples of unsaturated C₁₋₇ alkyl groups which have one or morecarbon-carbon double bonds (also referred to as “C₂₋₇alkenyl” groups)include, but are not limited to, ethenyl (vinyl, —CH═CH₂), 2-propenyl(allyl, —CH—CH═CH₂), isopropenyl (—C(CH₃)═CH₂), butenyl, pentenyl, andhexenyl.

Examples of unsaturated C₁₋₇ alkyl groups which have one or morecarbon-carbon triple bonds (also referred to as “C₂₋₇ alkynyl” groups)include, but are not limited to, ethynyl (ethinyl) and 2-propynyl(propargyl).

Examples of unsaturated alicyclic (carbocyclic) C₁₋₇ alkyl groups whichhave one or more carbon-carbon double bonds (also referred to as“C₃₋₇cycloalkenyl” groups) include, but are not limited to,unsubstituted groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl,and cyclohexenyl, as well as substituted groups (e.g., groups whichcomprise such groups) such as cyclopropenylmethyl andcyclohexenylmethyl.

C₃₋₂₀ heterocyclyl: The term “C₃₋₂₀ heterocyclyl”, as used herein,pertains to a monovalent moiety obtained by removing a hydrogen atomfrom a ring atom of a C₃₋₂₀ heterocyclic compound, said compound havingone ring, or two or more rings (e.g., spiro, fused, bridged), and havingfrom 3 to 20 ring atoms, atoms, of which from 1 to 10 are ringheteroatoms, and wherein at least one of said ring(s) is a heterocyclicring. Preferably, each ring has from 3 to 7 ring atoms, of which from 1to 4 are ring heteroatoms. “C₃₋₂₀” denotes ring atoms, whether carbonatoms or heteroatoms.

Examples of C₃₋₂₀ heterocyclyl groups having one nitrogen ring atominclude, but are not limited to, those derived from aziridine,azetidine, pyrrolidines (tetrahydropyrrole), pyrroline (e.g.,3-pyrroline, 2,5-dihydropyrrole), 2H-pyrrole or 3H-pyrrole (isopyrrole,isoazole), piperidine, dihydropyridine, tetrahydropyridine, and azepine.

Examples of C₃₋₂₀ heterocyclyl groups having one oxygen ring atominclude, but are not limited to, those derived from oxirane, oxetane,oxolane (tetrahydrofuran), oxole (dihydrofuran), oxane(tetrahydropyran), dihydropyran, pyran (C₆), and oxepin. Examples ofsubstituted C₃₋₂₀ heterocyclyl groups include sugars, in cyclic form,for example, furanoses and pyranoses, including, for example, ribose,lyxose, xylose, galactose, sucrose, fructose, and arabinose.

Examples of C₃₋₂₀ heterocyclyl groups having one sulphur ring atominclude, but are not limited to, those derived from thiirane, thietane,thiolane (tetrahydrothiophene), thiane (tetrahydrothiopyran), andthiepane.

Examples of C₃₋₂₀ heterocyclyl groups having two oxygen ring atomsinclude, but are not limited to, those derived from dioxolane, dioxane,and dioxepane.

Examples of C₃₋₂₀ heterocyclyl groups having two nitrogen ring atomsinclude, but are not limited to, those derived from imidazolidine,pyrazolidine (diazolidine), imidazoline, pyrazoline (dihydropyrazole),and piperazine.

Examples of C₃₋₂₀ heterocyclyl groups having one nitrogen ring atom andone oxygen ring atom include, but are not limited to, those derived fromtetrahydrooxazole, dihydrooxazole, tetrahydroisoxazole,dihydroisoxazole, morpholine, tetrahydrooxazine, dihydrooxazine, andoxazine.

Examples of C₃₋₂₀ heterocyclyl groups having one oxygen ring atom andone sulphur ring atom include, but are not limited to, those derivedfrom oxathiolane and oxathiane (thioxane).

Examples of C₃₋₂₀ heterocyclyl groups having one nitrogen ring atom andone sulphur ring atom include, but are not limited to, those derivedfrom thiazoline, thiazolidine, and thiomorpholine.

Other examples of C₃₋₂₀heterocyclyl groups include, but are not limitedto, oxadiazine and oxathiazine.

Examples of heterocyclyl groups which additionally bear one or more oxo(═O) groups, include, but are not limited to, those derived from:

C₅ heterocyclics, such as furanone, pyrone, pyrrolidone (pyrrolidinone),pyrazolone (pyrazolinone), imidazolidone, thiazolone, and isothiazolone;C₆ heterocyclics, such as piperidinone (piperidone), piperidinedione,piperazinone, piperazinedione, pyridazinone, and pyrimidinone (e.g.,cytosine, thymine, uracil), and barbituric acid;fused heterocyclics, such as oxindole, purinone (e.g., guanine),benzoxazolinone, benzopyrone (e.g., coumarin);cyclic anhydrides (—C(═O)—O—C(═O)— in a ring), including but not limitedto maleic anhydride, succinic anhydride, and glutaric anhydride;cyclic carbonates (—O—C(═O)—O— in a ring), such as ethylene carbonateand 1,2-propylene carbonate;imides (—C(═O)—NR—C(═O)— in a ring), including but not limited to,succinimide, maleimide, phthalimide, and glutarimide;lactones (cyclic esters, —O—C(═O)— in a ring), including, but notlimited to, β-propiolactone, γ-butyrolactone, δ-valerolactone(2-piperidone), and ε-caprolactone;lactams (cyclic amides, —NR—C(═O)— in a ring), including, but notlimited to, β-propiolactam, γ-butyrolactam (2-pyrrolidone),δ-valerolactam, and ε-caprolactam;cyclic carbamates (—O—C(═O)—NR— in a ring), such as 2-oxazolidone;cyclic ureas (—NR—C(═O)—NR— in a ring), such as 2-imidazolidone andpyrimidine-2,4-dione (e.g., thymine, uracil).

C₅₋₂₀ aryl: The term “C₅₋₂₀ aryl”, as used herein, pertains to amonovalent moiety obtained by removing a hydrogen atom from an aromaticring atom of a C₅₋₂₀ aromatic compound, said compound having one ring,or two or more rings (e.g., fused), and having from 5 to 20 ring atoms,and wherein at least one of said ring(s) is an aromatic ring.Preferably, each ring has from 5 to 7 ring atoms.

The ring atoms may be all carbon atoms, as in “carboaryl groups”, inwhich case the group may conveniently be referred to as a “C₅₋₂₀carboaryl” group.

Examples of C₅₋₂₀ aryl groups which do not have ring heteroatoms (i.e.C₅₋₂₀ carboaryl groups) include, but are not limited to, those derivedfrom benzene (i.e. phenyl) (C₆), naphthalene (C₁₀), anthracene (C₁₄),phenanthrene (C₁₄), naphthacene (C₁₈), and pyrene (C₁₆).

Examples of aryl groups which comprise fused rings, one of which is notan aromatic ring, include, but are not limited to, groups derived fromindene and fluorene.

Alternatively, the ring atoms may include one or more heteroatoms,including but not limited to oxygen, nitrogen, and sulphur, as in“heteroaryl groups”. In this case, the group may conveniently bereferred to as a “C₅₋₂₀ heteroaryl” group, wherein “C₅₋₂₀” denotes ringatoms, whether carbon atoms or heteroatoms. Preferably, each ring hasfrom 5 to 7 ring atoms, of which from 0 to 4 are ring heteroatoms.

Examples of C₅₋₂₀ heteroaryl groups include, but are not limited to, C₅heteroaryl groups derived from furan (oxole), thiophene (thiole),pyrrole (azole), imidazole (1,3-diazole), pyrazole (1,2-diazole),triazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, andoxatriazole; and C₆ heteroaryl groups derived from isoxazine, pyridine(azine), pyridazine (1,2-diazine), pyrimidine (1,3-diazine; e.g.,cytosine, thymine, uracil), pyrazine (1,4-diazine), triazine, tetrazole,and oxadiazole (furazan).

Examples of C₅₋₂₀ heterocyclic groups (some of which are C₅₋₂₀heteroaryl groups) which comprise fused rings, include, but are notlimited to, Cg heterocyclic groups derived from benzofuran,isobenzofuran, indole, isoindole, purine (e.g., adenine, guanine),benzothiophene, benzimidazole; C₁₀ heterocyclic groups derived fromquinoline, isoquinoline, benzodiazine, pyridopyridine, quinoxaline; C₁₃heterocyclic groups derived from carbazole, dibenzothiophene,dibenzofuran; C₁₄ heterocyclic groups derived from acridine, xanthene,phenoxathiin, phenazine, phenoxazine, phenothiazine.

The above C₁₋₇ alkyl, C₃₋₂₀ heterocyclyl and C₅₋₂₀ aryl groups whetheralone or part of another substituent, may themselves optionally besubstituted with one or more groups selected from themselves and theadditional substituents listed below.

Halo: —F, —Cl, —Br, and —I.

Hydroxy: —OH.

Ether: —OR, wherein R is an ether substituent, for example, a C₁₋₇ alkylgroup (also referred to as a C₁₋₇ alkoxy group, discussed below), aC₃₋₂₀ heterocyclyl group (also referred to as a C₃₋₂₀ heterocyclyloxygroup), or a C₅₋₂₀ aryl group (also referred to as a C₅₋₂₀ aryloxygroup), preferably a C₁₋₇ alkyl group.

C₁₋₇ alkoxy: —OR, wherein R is a C₁₋₇ alkyl group. Examples of C₁₋₇alkoxy groups include, but are not limited to, —OCH₃ (methoxy), —OCH₂CH₃(ethoxy) and —OC(CH₃)₃ (tert-butoxy).

Oxo (keto, -one): ═O. Examples of cyclic compounds and/or groups having,as a substituent, an oxo group (═O) include, but are not limited to,carbocyclics such as cyclopentanone and cyclohexanone; heterocyclics,such as pyrone, pyrrolidone, pyrazolone, pyrazolinone, piperidone,piperidinedione, piperazinedione, and imidazolidone; cyclic anhydrides,including but not limited to maleic anhydride and succinic anhydride;cyclic carbonates, such as propylene carbonate; imides, including butnot limited to, succinimide and maleimide; lactones (cyclic esters,—O—C(═O)— in a ring), including, but not limited to, β-propiolactone,γ-butyrolactone, δ-valerolactone, and ε-caprolactone; and lactams(cyclic amides, —NH—C(═O)— in a ring), including, but not limited to,β-propiolactam, γ-butyrolactam (2-pyrrolidone), δ-valerolactam, andε-caprolactam.

Imino (imine): ═NR, wherein R is an imino substituent, for example,hydrogen, C₁₋₇alkyl group, a C₃₋₂₀heterocyclyl group, or a C₅₋₂₀ arylgroup, preferably hydrogen or a C₁₋₇ alkyl group. Examples of estergroups include, but are not limited to, ═NH, ═NMe, ═NEt, and ═NPh.

Formyl (carbaldehyde, carboxaldehyde): —C(═O)H.

Acyl (keto): —C(═O)R, wherein R is an acyl substituent, for example, aC₁₋₇alkyl group (also referred to as C₁₋₇ alkylacyl or C₁₋₇ alkanoyl), aC₃₋₂₀ heterocyclyl group (also referred to as C₃₋₂₀ heterocyclylacyl),or a C₅₋₂₀ aryl group (also referred to as C₅₋₂₀ arylacyl), preferably aC₁₋₇ alkyl group. Examples of acyl groups include, but are not limitedto, —C(═O)CH₃ (acetyl), —C(═O)CH₂CH₃ (propionyl), —C(═O)C(CH₃)₃(butyryl), and —C(═O)Ph (benzoyl, phenone).

Carboxy (carboxylic acid): —COOH.

Ester (carboxylate, carboxylic acid ester, oxycarbonyl): —C(═O)OR,wherein R is an ester substituent, for example, a C₁₋₇ alkyl group, aC₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group, preferably a C₁₋₇alkylgroup. Examples of ester groups include, but are not limited to,—C(═O)OCH₃, —C(═O)OCH₂CH₃, —C(═O)OC(CH₃)₃, and —C(═O)OPh.

Acyloxy (reverse ester): —OC(═O)R, wherein R is an acyloxy substituent,for example, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀aryl group, preferably a C₁₋₇alkyl group. Examples of acyloxy groupsinclude, but are not limited to, —OC(═O)CH₃ (acetoxy), —OC(═O)CH₂CH₃,—OC(═O)C(CH₃)₃, —OC(═O)Ph, and —OC(═O)CH₂Ph.

Amido (carbamoyl, carbamyl, aminocarbonyl, carboxamide): —C(═O)NR¹R²,wherein R¹ and R² are independently amino substituents, as defined foramino groups. Examples of amido groups include, but are not limited to,—C(═O)NH₂, —C(═O)NHCH₃, —C(═O)N(CH₃)₂, —C(═O)NHCH₂CH₃, and—C(═O)N(CH₂CH₃)₂, as well as amido groups in which R¹ and R², togetherwith the nitrogen atom to which they are attached, form a heterocyclicstructure as in, for example, piperidinocarbonyl, morpholinocarbonyl,thiomorpholinocarbonyl, and piperazinocarbonyl.

Acylamido (acylamino): —NR¹C(═O)R², wherein R¹ is an amide substituent,for example, hydrogen, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group,or a C₅₋₂₀ aryl group, preferably hydrogen or a C₁₋₇ alkyl group, and R²is an acyl substituent, for example, a C₁₋₇ alkyl group, a C₃₋₂₀heterocyclyl group, or a C₅₋₂₀ aryl group, preferably hydrogen or a C₁₋₇alkyl group. Examples of acylamide groups include, but are not limitedto, —NHC(═O)CH₃, —NHC(═O)CH₂CH₃, and —NHC(═O)Ph. R¹ and R² may togetherform a cyclic structure, as in, for example, succinimidyl, maleimidyland phthalimidyl:

Acylureido: —N(R¹)C(O)NR²C(O)R³ wherein R¹ and R² are independentlyureido substituents, for example, hydrogen, a C₁₋₇ alkyl group, a C₃₋₂₀heterocyclyl group, or a C₅₋₂₀ aryl group, preferably hydrogen or a C₁₋₇alkyl group. R³ is an acyl group as defined for acyl groups. Examples ofacylureido groups include, but are not limited to, —NHCONHC(O)H,—NHCONMeC(O)H, —NHCONEtC(O)H, —NHCONMeC(O)Me, —NHCONEtC(O)Et,—NMeCONHC(O)Et, —NMeCONHC(O)Me, —NMeCONHC(O)Et, —NMeCONMeC(O)Me,—NMeCONEtC(O)Et, and —NMeCONHC(O)Ph.

Carbamate: —NR¹—C(O)—OR² wherein R¹ is an amino substituent as definedfor amino groups and R² is an ester group as defined for ester groups.Examples of carbamate groups include, but are not limited to,—NH—C(O)—O-Me, —NMe-C(O)—O-Me, —NH—C(O)—O-Et, —NMe-C(O)—O-t-butyl, and—NH—C(O)—O-Ph.

Thioamido (thiocarbamyl): —C(═S)NR¹R², wherein R¹ and R² areindependently amino substituents, as defined for amino groups. Examplesof amido groups include, but are not limited to, —C(═S)NH₂, —C(═S)NHCH₃,—C(═S)N(CH₃)₂, and —C(═S)NHCH₂CH₃.

Tetrazolyl: a five membered aromatic ring having four nitrogen atoms andone carbon atom,

Amino: —NR¹R², wherein R¹ and R² are independently amino substituents,for example, hydrogen, a C₁₋₇ alkyl group (also referred to as C₁₋₇alkylamino or di-C₁₋₇ alkylamino), a C₃₋₂₀ heterocyclyl group, or aC₅₋₂₀ aryl group, preferably H or a C₁₋₇alkyl group, or, in the case ofa “cyclic” amino group, R¹ and R², taken together with the nitrogen atomto which they are attached, form a heterocyclic ring having from 4 to 8ring atoms. Examples of amino groups include, but are not limited to,—NH₂, —NHCH₃, —NHC(CH₃)₂, —N(CH₃)₂, —N(CH₂CH₃)₂, and —NHPh. Examples ofcyclic amino groups include, but are not limited to, aziridino,azetidino, pyrrolidino, piperidino, piperazino, morpholino, andthiomorpholino.

Imino: ═NR, wherein R is an imino substituent, for example, hydrogen, aC₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group,preferably H or a C₁₋₇ alkyl group.

Amidine: —C(═NR)NR₂, wherein each R is an amidine substituent, forexample, hydrogen, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or aC₅₋₂₀ aryl group, preferably H or a C₁₋₇ alkyl group. An example of anamidine group is —C(═NH)NH₂.

Carbazoyl (hydrazinocarbonyl): —C(O)—NN—R¹ wherein R¹ is an aminosubstituent as defined for amino groups. Examples of azino groupsinclude, but are not limited to, —C(O)—NN—H, —C(O)—NN-Me, —C(O)—NN-Et,—C(O)—NN-Ph, and —C(O)—NN—CH₂-Ph.

Nitro: —NO₂.

Nitroso: —NO.

Azido: —N₃.

Cyano (nitrile, carbonitrile): —CN.

Isocyano: —NC.

Cyanato: —OCN.

Isocyanato: —NCO.

Thiocyano (thiocyanato): —SCN.

Isothiocyano (isothiocyanato): —NCS.

Sulfhydryl (thiol, mercapto): —SH.

Thioether (sulfide): —SR, wherein R is a thioether substituent, forexample, a C₁₋₇ alkyl group (also referred to as a C₁₋₇ alkylthiogroup), a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group, preferably aC₁₋₇ alkyl group. Examples of C₁₋₇ alkylthio groups include, but are notlimited to, —SCH₃ and —SCH₂CH₃.

Disulfide: —SS—R, wherein R is a disulfide substituent, for example, aC₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group,preferably a C₁₋₇ alkyl group (also referred to herein as C₁₋₇ alkyldisulfide). Examples of C₁₋₇ alkyl disulfide groups include, but are notlimited to, —SSCH₃ and —SSCH₂CH₃.

Sulfone (sulfonyl): —S(═O)₂R, wherein R is a sulfone substituent, forexample, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ arylgroup, preferably a C₁₋₇ alkyl group. Examples of sulfone groupsinclude, but are not limited to, —S(═O)₂CH₃ (methanesulfonyl, mesyl),—S(═O)₂CF₃ (triflyl), —S(═O)₂CH₂CH₃, —S(═O)₂C₄F₉ (nonaflyl),—S(═O)₂CH₂CF₃ (tresyl), —S(═O)₂Ph (phenylsulfonyl),4-methylphenylsulfonyl (tosyl), 4-bromophenylsulfonyl (brosyl), and4-nitrophenyl (nosyl).

Sulfine (sulfinyl, sulfoxide): —S(═O)R, wherein R is a sulfinesubstituent, for example, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclylgroup, or a C₅₋₂₀ aryl group, preferably a C₁₋₇ alkyl group. Examples ofsulfine groups include, but are not limited to, —S(═O)CH₃ and—S(═O)CH₂CH₃.

Sulfonyloxy: —OS(═O)₂R, wherein R is a sulfonyloxy substituent, forexample, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ arylgroup, preferably a C₁₋₇ alkyl group. Examples of sulfonyloxy groupsinclude, but are not limited to, —OS(═O)₂CH₃ and —OS(═O)₂CH₂CH₃.

Sulfinyloxy: —OS(═O)R, wherein R is a sulfinyloxy substituent, forexample, a C₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ arylgroup, preferably a C₁₋₇ alkyl group. Examples of sulfinyloxy groupsinclude, but are not limited to, —OS(═O)CH₃ and —OS(═O)CH₂CH₃.

Sulfamino: —NR¹S(═O)₂OH, wherein R¹ is an amino substituent, as definedfor amino groups. Examples of sulfamino groups include, but are notlimited to, —NHS(═O)₂OH and —N(CH₃)S(═O)₂OH.

Sulfonamino: —NR¹S(═O)₂R, wherein R¹ is an amino substituent, as definedfor amino groups, and R is a sulfonamino substituent, for example, aC₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group,preferably a C₁₋₇ alkyl group. Examples of sulfonamino groups include,but are not limited to, —NHS(═O)₂CH₃ and —N(CH₃)S(═O)₂C₆H₅.

Sulfinamino: —NR¹S(═O)R, wherein R¹ is an amino substituent, as definedfor amino groups, and R is a sulfinamino substituent, for example, aC₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group,preferably a C₁₋₇ alkyl group. Examples of sulfinamino groups include,but are not limited to, —NHS(═O)CH₃ and —N(CH₃)S(═O)C₆H₅.

Sulfamyl: —S(═O)NR¹R², wherein R¹ and R² are independently aminosubstituents, as defined for amino groups. Examples of sulfamyl groupsinclude, but are not limited to, —S(═O)NH₂, —S(═O)NH(CH₃),—S(═O)N(CH₃)₂, —S(═O)NH(CH₂CH₃), —S(═O)N(CH₂CH₃)₂, and —S(═O)NHPh.

Sulfonamino: —NR¹S(═O)₂R, wherein R¹ is an amino substituent, as definedfor amino groups, and R is a sulfonamino substituent, for example, aC₁₋₇ alkyl group, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group,preferably a C₁₋₇ alkyl group. Examples of sulfonamino groups include,but are not limited to, —NHS(═O)₂CH₃ and —N(CH₃)S(═O)₂C₆H₅. A specialclass of sulfonamino groups are those derived from sultams—in thesegroups one of R¹ and R is a C₅₋₂₀ aryl group, preferably phenyl, whilstthe other of R¹ and R is a bidentate group which links to the C₅₋₂₀ arylgroup, such as a bidentate group derived from a C₁₋₇ alkyl group.Examples of such groups include, but are not limited to:

Phosphoramidite: —OP(OR¹)—NR² ₂, where R¹ and R² are phosphoramiditesubstituents, for example, —H, a (optionally substituted) C₁₋₇ alkylgroup, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group, preferably —H,a C₁₋₇ alkyl group, or a C₅₋₂₀ aryl group. Examples of phosphoramiditegroups include, but are not limited to, —OP(OCH₂CH₃)—N(CH₃)₂,—OP(OCH₂CH₃)—N(i-Pr)₂, and —OP(OCH₂CH₂CN)—N(i-Pr)₂.

Phosphoramidate: —OP(═O)(OR¹)—NR² ₂, where R¹ and R² are phosphoramidatesubstituents, for example, —H, a (optionally substituted) C₁₋₇ alkylgroup, a C₃₋₂₀ heterocyclyl group, or a C₅₋₂₀ aryl group, preferably —H,a C₁₋₇ alkyl group, or a C₅₋₂₀ aryl group. Examples of phosphoramidategroups include, but are not limited to, —OP(═O)(OCH₂CH₃)—N(CH₃)₂,—OP(═O)(OCH₂CH₃)—N(i-Pr)₂, and —OP(═O)(OCH₂CH₂CN)—N(i-Pr)₂.

In many cases, substituents may themselves be substituted. For example,a C₁₋₇ alkoxy group may be substituted with, for example, a C₁₋₇ alkyl(also referred to as a C₁₋₇ alkyl-C₁₋₇alkoxy group), for example,cyclohexylmethoxy, a C₃₋₂₀ heterocyclyl group (also referred to as aC₅₋₂₀ aryl-C₁₋₇ alkoxy group), for example phthalimidoethoxy, or a C₅₋₂₀aryl group (also referred to as a C₅₋₂₀aryl-C₁₋₇alkoxy group), forexample, benzyloxy.

C₁₋₅ Alkylene: The term “C₁₋₅ alkylene”, as used herein, pertains to abidentate moiety obtained by removing two hydrogen atoms, either bothfrom the same carbon atom, or one from each of two different carbonatoms, of an aliphatic linear hydrocarbon compound having from 1 to 5carbon atoms (unless otherwise specified), which may be saturated,partially unsaturated, or fully unsaturated. Thus, the term “alkylene”includes the sub-classes alkenylene, alkynylene, etc., discussed below.

Examples of saturated C₁₋₅ alkylene groups include, but are not limitedto, —(CH₂)_(n)— where n is an integer from 1 to 5, for example, —CH₂—(methylene), —CH₂CH₂— (ethylene), —CH₂CH₂CH₂— (propylene), and—CH₂CH₂CH₂CH₂— (butylene).

Examples of partially unsaturated C₁₋₅ alkylene groups include, but isnot limited to, —CH═CH— (vinylene), —CH═CH—CH₂—, —CH₂—CH═CH₂—,—CH═CH—CH₂—CH₂—, —CH═CH—CH₂—CH₂—CH₂—, —CH═CH—CH═CH— and—CH═CH—CH═CH—CH₂—.

The substituent groups listed above may be substituents on an alkylenegroup.

Includes Other Forms

Included in the above are the well known ionic, salt, solvate, andprotected forms of these substituents. For example, a reference tocarboxylic acid (—COOH) also includes the anionic (carboxylate) form(—COO⁻), a salt or solvate thereof, as well as conventional protectedforms. Similarly, a reference to an amino group includes the protonatedform (—N⁺HR¹R²), a salt or solvate of the amino group, for example, ahydrochloride salt, as well as conventional protected forms of an aminogroup. Similarly, a reference to a hydroxyl group also includes theanionic form (—O⁻), a salt or solvate thereof, as well as conventionalprotected forms of a hydroxyl group.

Isomers, Salts, Solvates, Protected Forms, and Prodrugs

Certain compounds may exist in one or more particular geometric,optical, enantiomeric, diasteriomeric, epimeric, stereoisomeric,tautomeric, conformational, or anomeric forms, including but not limitedto, cis- and trans-forms; E- and Z-forms; c-, t-, and r-forms; endo- andexo-forms; R-, S-, and meso-forms; D- and L-forms; d- and I-forms; (+)and (−) forms; keto-, enol-, and enolate-forms; syn- and anti-forms;synclinal- and anticlinal-forms; α- and β-forms; axial and equatorialforms; boat-, chair-, twist-, envelope-, and halfchair-forms; andcombinations thereof, hereinafter collectively referred to as “isomers”(or “isomeric forms”).

Note that, except as discussed below for tautomeric forms, specificallyexcluded from the term “isomers”, as used herein, are structural (orconstitutional) isomers (i.e. isomers which differ in the connectionsbetween atoms rather than merely by the position of atoms in space). Forexample, a reference to a methoxy group, —OCH₃, is not to be construedas a reference to its structural isomer, a hydroxymethyl group, —CH₂OH.Similarly, a reference to ortho-chlorophenyl is not to be construed as areference to its structural isomer, meta-chlorophenyl. However, areference to a class of structures may well include structurallyisomeric forms falling within that class (e.g., C₁₋₇ alkyl includesn-propyl and iso-propyl; butyl includes n-, iso-, sec-, and tert-butyl;methoxyphenyl includes ortho-, meta-, and para-methoxyphenyl).

The above exclusion does not pertain to tautomeric forms, for example,keto-, enol-, and enolate-forms, as in, for example, the followingtautomeric pairs: keto/enol (illustrated below), imine/enamine,amide/imino alcohol, amidine/amidine, nitroso/oxime,thioketone/enethiol, N-nitroso/hyroxyazo, and nitro/aci-nitro.

Note that specifically included in the term “isomer” are compounds withone or more isotopic substitutions. For example, H may be in anyisotopic form, including ¹H, ²H (D), and ³H (T); C may be in anyisotopic form, including ¹²C, ¹³C, and ¹⁴C; 0 may be in any isotopicform, including ¹⁶O and ¹⁸O; and the like.

Unless otherwise specified, a reference to a particular compoundincludes all such isomeric forms, including (wholly or partially)racemic and other mixtures thereof. Methods for the preparation (e.g.asymmetric synthesis) and separation (e.g., fractional crystallisationand chromatographic means) of such isomeric forms are either known inthe art or are readily obtained by adapting the methods taught herein,or known methods, in a known manner.

Unless otherwise specified, a reference to a particular compound alsoincludes ionic, salt, solvate, and protected forms of thereof, forexample, as discussed below.

It may be convenient or desirable to prepare, purify, and/or handle acorresponding salt of the active compound, for example, apharmaceutically-acceptable salt. Examples of pharmaceuticallyacceptable salts are discussed in Berge et al., 1977, “PharmaceuticallyAcceptable Salts”, J. Pharm. Sci., Vol. 66, pp. 1-19.

For example, if the compound is anionic, or has a functional group whichmay be anionic (e.g., —COOH may be —COO⁻), then a salt may be formedwith a suitable cation. Examples of suitable inorganic cations include,but are not limited to, alkali metal ions such as Na⁺ and K⁺, alkalineearth cations such as Ca²⁺ and Mg²⁺, and other cations such as Al³⁺.Examples of suitable organic cations include, but are not limited to,ammonium ion (i.e., NH₄ ⁺) and substituted ammonium ions (e.g., NH₃R⁺,NH₂R₂ ⁺, NHR₃ ⁺, NR₄ ⁺). Examples of some suitable substituted ammoniumions are those derived from: ethylamine, diethylamine,dicyclohexylamine, triethylamine, butylamine, ethylenediamine,ethanolamine, diethanolamine, piperazine, benzylamine,phenylbenzylamine, choline, meglumine, and tromethamine, as well asamino acids, such as lysine and arginine. An example of a commonquaternary ammonium ion is N(CH₃)₄ ⁺.

If the compound is cationic, or has a functional group which may becationic (e.g., —NH₂ may be —NH₃ ⁺), then a salt may be formed with asuitable anion. Examples of suitable inorganic anions include, but arenot limited to, those derived from the following inorganic acids:hydrochloric, hydrobromic, hydroiodic, sulphuric, sulphurous, nitric,nitrous, phosphoric, and phosphorous. Examples of suitable organicanions include, but are not limited to, those derived from the followingorganic acids: acetic, propionic, succinic, glycolic, stearic, palmitic,lactic, malic, pamoic, tartaric, citric, gluconic, ascorbic, maleic,hydroxymaleic, phenylacetic, glutamic, aspartic, benzoic, cinnamic,pyruvic, salicyclic, sulfanilic, 2-acetyoxybenzoic, fumaric,phenylsulfonic, toluenesulfonic, methanesulfonic, ethanesulfonic, ethanedisulfonic, oxalic, pantothenic, isethionic, valeric, lactobionic, andgluconic. Examples of suitable polymeric anions include, but are notlimited to, those derived from the following polymeric acids: tannicacid, carboxymethyl cellulose.

It may be convenient or desirable to prepare, purify, and/or handle acorresponding solvate of the active compound. The term “solvate” is usedherein in the conventional sense to refer to a complex of solute (e.g.active compound, salt of active compound) and solvent. If the solvent iswater, the solvate may be conveniently referred to as a hydrate, forexample, a mono-hydrate, a di-hydrate, a tri-hydrate, etc.

It may be convenient or desirable to prepare, purify, and/or handle theactive compound in a chemically protected form. The term “chemicallyprotected form”, as used herein, pertains to a compound in which one ormore reactive functional groups are protected from undesirable chemicalreactions, that is, are in the form of a protected or protecting group(also known as a masked or masking group or a blocked or blockinggroup). By protecting a reactive functional group, reactions involvingother unprotected reactive functional groups can be performed, withoutaffecting the protected group; the protecting group may be removed,usually in a subsequent step, without substantially affecting theremainder of the molecule. See, for example, Protective Groups inOrganic Synthesis (T. Green and P. Wuts, Wiley, 1999).

For example, a hydroxy group may be protected as an ether (—OR) or anester (—OC(═O)R), for example, as: a t-butyl ether; a benzyl, benzhydryl(diphenylmethyl), or trityl (triphenylmethyl)ether; a trimethylsilyl ort-butyldimethylsilyl ether; or an acetyl ester (—OC(═O)CH₃, —OAc).

For example, an aldehyde or ketone group may be protected as an acetalor ketal, respectively, in which the carbonyl group (>C═O) is convertedto a diether (>C(OR)₂), by reaction with, for example, a primaryalcohol. The aldehyde or ketone group is readily regenerated byhydrolysis using a large excess of water in the presence of acid.

For example, an amine group may be protected, for example, as an amideor a urethane, for example, as: a methyl amide (—NHCO—CH₃); a benzyloxyamide (—NHCO—OCH₂C₆H₅, —NH-Cbz); as a t-butoxy amide (—NHCO—OC(CH₃)₃,—NH-Boc); a 2-biphenyl-2-propoxy amide (—NHCO—OC(CH₃)₂C₆H₄C₆H₅,—NH-Bpoc), as a 9-fluorenylmethoxy amide (—NH-Fmoc), as a6-nitroveratryloxy amide (—NH-Nvoc), as a 2-trimethylsilylethyloxy amide(—NH-Teoc), as a 2,2,2-trichloroethyloxy amide (—NH-Troc), as anallyloxy amide (—NH-Alloc), as a 2(-phenylsulphonyl)ethyloxy amide(—NH-Psec); or, in suitable cases, as an N-oxide (>NO$).

For example, a carboxylic acid group may be protected as an ester forexample, as: an C₁₋₇ alkyl ester (e.g. a methyl ester; a t-butyl ester);a C₁₋₇ haloalkyl ester (e.g., a C₁₋₇ trihaloalkyl ester); a triC₁₋₇alkylsilyl-C₁₋₇ alkyl ester; or a C₅₋₂₀ aryl-C₁₋₇ alkyl ester (e.g. abenzyl ester; a nitrobenzyl ester); or as an amide, for example, as amethyl amide.

For example, a thiol group may be protected as a thioether (—SR), forexample, as: a benzyl thioether; an acetamidomethyl ether(—S—CH₂NHC(═O)CH₃).

It may be convenient or desirable to prepare, purify, and/or handle theactive compound in the form of a prodrug. The term “prodrug”, as usedherein, pertains to a compound which, when metabolised (e.g. in vivo),yields the desired active compound. Typically, the prodrug is inactive,or less active than the active compound, but may provide advantageoushandling, administration, or metabolic properties.

For example, some prodrugs are esters of the active compound (e.g. aphysiologically acceptable metabolically labile ester). Duringmetabolism, the ester group (—C(═O)OR) is cleaved to yield the activedrug. Such esters may be formed by esterification, for example, of anyof the carboxylic acid groups (—C(═O)OH) in the parent compound, with,where appropriate, prior protection of any other reactive groups presentin the parent compound, followed by deprotection if required. Examplesof such metabolically labile esters include those wherein R is C₁₋₇alkyl (e.g. -Me, -Et); C₁₋₇ aminoalkyl (e.g. aminoethyl;2-(N,N-diethylamino)ethyl; 2-(4-morpholino)ethyl); and acyloxy-C₁₋₇alkyl(e.g. acyloxymethyl; acyloxyethyl; e.g. pivaloyloxymethyl;acetoxymethyl; 1-acetoxyethyl;1-(1-methoxy-1-methyl)ethyl-carbonxyloxyethyl; 1-(benzoyloxy)ethyl;isopropoxy-carbonyloxymethyl; 1-isopropoxy-carbonyloxyethyl;cyclohexyl-carbonyloxymethyl; 1-cyclohexyl-carbonyloxyethyl;cyclohexyloxy-carbonyloxymethyl; 1-cyclohexyloxy-carbonyloxyethyl;(4-tetrahydropyranyloxy) carbonyloxymethyl;1-(4-tetrahydropyranyloxy)carbonyloxyethyl;(4-tetrahydropyranyl)carbonyloxymethyl; and1-(4-tetrahydropyranyl)carbonyloxyethyl).

Also, some prodrugs are activated enzymatically to yield the activecompound, or a compound which, upon further chemical reaction, yieldsthe active compound. For example, the prodrug may be a sugar derivativeor other glycoside conjugate, or may be an amino acid ester derivative.

Selective Inhibition

‘Selective inhibition’ means the inhibition of one enzyme to a greaterextent than the inhibition of one or more other enzymes. Thisselectivity is measurable by comparing the concentration of a compoundrequired to inhibit 50% of the activity (IC₅₀) of one enzyme against theconcentration of the same compound required to inhibit 50% of theactivity (IC₅₀) of the other enzyme (see below). The result is expressedas a ratio. If the ratio is greater than 1, then the compound testedexhibits some selectivity in its inhibitory action.

The compounds of the present invention preferably exhibit a selectivityof greater than 3, 10, 20 or 50 against DNA-PK over PI 3-kinase.

The compounds of the present invention preferably exhibit a selectivityof greater than 5, 10, 50 or 100 against DNA-PK over ATM.

It is preferred that the IC₅₀s used to determine selectivity aredetermined using the methods described in WO 03/024949, which is hereinincorporated by reference.

Further Preferences

When Q is —NH—C(═O)—, X is preferably NR⁴R⁵. It is further preferredthat Y is an optionally substituted C₁₋₃ alkylene group, more preferablyan optionally substituted C₁₋₂ alkylene group and most preferably a C₁₋₂alkylene group.

When Q is —O— and X is NR⁴R⁵, then Y is preferably an optionallysubstituted C₁₋₃ alkylene group, more preferably an optionallysubstituted C₁₋₂ alkylene group and most preferably a C₁₋₂ alkylenegroup.

In some embodiments, R⁴ and R⁵ are preferably independently selectedfrom H and optionally substituted C₁₋₇ alkyl, more preferably H andoptionally substituted C₁₋₄ alkyl and most preferably H and optionallysubstituted C₁₋₂ alkyl. Preferred optional substitutents include, butare not limited to, hydroxy, methoxy, —NH₂, optionally substitutedC₆-aryl and optionally substituted C₅₋₆ heterocyclyl.

In other embodiments, R⁴ and R⁵ form, together with the nitrogen atom towhich they are attached, an optionally substituted nitrogen containingheterocylic ring having from 4 to 8 ring atoms. Preferably, theheterocyclic ring has 5 to 7 ring atoms. Examples of preferred groupsinclude, morpholino, piperidinyl, piperazinyl, homopiperazinyl andtetrahydropyrrolo. These groups may be substituted, and a particularlypreferred group is optionally substituted piperazinyl, where thesubstituent is preferably on the para-nitrogen atom. PreferredN-substituents include optionally substituted C₁₋₄ alkyl, optionallysubstituted C₆ aryl and acyl (with a C₁₋₄ alkyl group as the acylsubstituent).

Some preferred compounds of the present invention can be represented byformula II:

wherein:

R¹, R² and Q are as defined for formula I;

n is 1 to 7, preferably 1-4 and most preferably 1 or 2; and

R⁸ is selected from hydrogen, optionally substituted C₁₋₇ alkyl(preferably optionally substituted C₁₋₄ alkyl), optionally substitutedC₅₋₂₀ aryl (preferably optionally substituted C₆ aryl), and acyl (wherethe acyl substituent is preferably C₁₋₄ alkyl).

The preferences for R⁶ and R⁷ may be the same as for R⁴ and R⁵ expressedabove.

In formula I (and formula II), when R¹ and R² form, along with thenitrogen atom to which they are attached, a heterocyclic ring havingfrom 4 to 8 atoms, this may form part of a C₄₋₂₀ heterocyclyl groupdefined above (except with a minimum of 4 ring atoms), which mustcontain at least one nitrogen ring atom. It is preferred that R¹ and R²form, along with the nitrogen atom to which they are attached, aheterocyclic ring having 5, 6 or 7 atoms, more preferably 6 ring atoms.

Single rings having one nitrogen atom include azetidine, azetidine,pyrrolidine (tetrahydropyrrole), pyrroline (e.g., 3-pyrroline,2,5-dihydropyrrole), 2H-pyrrole or 3H-pyrrole (isopyrrole, isoazole),piperidine, dihydropyridine, tetrahydropyridine, and azepine; twonitrogen atoms include imidazolidine, pyrazolidine (diazolidine),imidazoline, pyrazoline (dihydropyrazole), and piperazine; one nitrogenand one oxygen include tetrahydrooxazole, dihydrooxazole,tetrahydroisoxazole, dihydroisoxazole, morpholine, tetrahydrooxazine,dihydrooxazine, and oxazine; one nitrogen and one sulphur includethiazoline, thiazolidine, and thiomorpholine.

Preferred rings are those containing one heteroatom in addition to thenitrogen, and in particular, the preferred heteroatoms are oxygen andsulphur. Thus preferred groups include morpholino, thiomorpholino,thiazolinyl. Preferred groups without a further heteroatom includepyrrolidino.

The most preferred groups are morpholino and thiomorpholino.

As mentioned above, these heterocyclic groups may themselves besubstituted; a preferred class of substituent is a C₁₋₇ alkyl group.When the heterocyclic group is morpholino, the substituent group orgroups are preferably methyl or ethyl, and more preferably methyl. Asole methyl substituent is most preferably in the 2 position.

As well as the single ring groups listed above, rings with bridges orcross-links are also envisaged. Examples of these types of ring wherethe group contains a nitrogen and an oxygen atom are:

These are named 8-oxa-3-aza-bicyclo[3.2.1]oct-3-yl,6-oxa-3-aza-bicyclo[3.1.0]hex-3-yl, 2-oxa-5-aza-bicyclo[2.2.1]hept-5-yl,and 7-oxa-3-aza-bicyclo[4.1.0]hept-3-yl, respectively.

GENERAL SYNTHESIS METHODS

Compounds of formula I, where Q is —NH—C(═O)— can be represented asFormula 1:

These compounds, where —Y—X is not C₁₋₇ alkyl, can be made fromcompounds of formula 2:

wherein L is chloro or bromo, by reacting with the appropriate amine orthiol. This reaction can be carried at room temperature, or may beheated, if necessary.

Compounds of formula 2 can be synthesised by the reaction of a compoundof formula 3:

with a compound of formula 4:

in the presence of an organic base, for example, triethylamine.

Compounds of formula 1 where —Y—X is C₁₋₇ alkyl can be synthesised bythe reaction of a compound of formula 3 with a compound of formula 4a:

in the presence of an organic base, for example, triethylamine.

The compounds of formula 3 may be synthesised by reducing a compound offormula 5:

using an appropriate reducing agent, for example, zinc in acetic acid.

Compounds of formula 5 can be synthesised by the Suzuki-Miyaura couplingof compounds of formula 6 and 7:

This method is described in WO 03/024949 (Synthesis route 7c)—theboronic ester used can be replaced by equivalent boron groups.

Routes to compounds of formula 7 are described in WO 03/024949(Synthesis Route 6).

Compounds of formula 1 where —Y—X is C₁₋₇ alkyl can also be synthesisedby the Suzuki-Miyaura coupling compounds of formula 8 and 9:

Compounds of formula 8 may be synthesised from a compound of formula 10:

by reaction with the appropriate acid anhydride in, for example,pyridine.

Compounds of formula 9 may be synthesised from compounds of formula 8 byreaction with the appropriate boron reagent.

Compounds of formula I, where Q is —O— and X is selected from SR³ orNR⁴R⁵ can be represented as Formula 11:

wherein X′ represents SR³ or NR⁴R⁵. These compounds can be synthesisedfrom compounds of formula 12:

wherein L is chloro or bromo, by reacting with the appropriate amine orthiol. This reaction can be carried at room temperature, or may beheated, if necessary.

Compounds of formula 12 can be synthesised by the reaction of a compoundof formula 13:

with a compound of formula 14:

in the presence of, for example, potassium carbonate.

Compounds of formula 13 can be synthesised from compounds of formula 3using a diazotisation-hydrolysis procedure. This first converts theamino group into the diazonium fluoroborate salt, for example, usingHBF₄ and butyl nitrite, which is then hydrolysed using, for example,aqueous copper (I) oxide-copper (II) nitrate.

Compounds of formula I, where Q is —O— and X is —C(═O)—NR⁶R⁷ can berepresented as Formula 15:

wherein X″ represents NR⁶R⁷. These compounds can be synthesised fromcompounds of formula 16:

by reaction with the appropriate amine in the presence of HBTU and HOBT.

Compounds of formula 16 can be made from compounds of formula 17:

by reaction with sodium hydroxide in methanol. The compounds of formula17 can be synthesised from compounds of formula 10 by reaction with acompound of formula 18:

in the presence of, for example, potassium carbonate.

USE OF COMPOUNDS OF THE INVENTION

The present invention provides active compounds, specifically, active8-[1-substituted-dibenzothiophen-4-yl]-2-morpholin-4-yl-chromen-4-ones.

The term “active”, as used herein, pertains to compounds which arecapable of inhibiting DNA-PK activity, and specifically includes bothcompounds with intrinsic activity (drugs) as well as prodrugs of suchcompounds, which prodrugs may themselves exhibit little or no intrinsicactivity.

One assay which may be used in order to assess the DNA-PK inhibitionoffered by a particular compound is described in the examples below.

The present invention further provides a method of inhibiting DNA-PKinhibition in a cell, comprising contacting said cell with an effectiveamount of an active compound, preferably in the form of apharmaceutically acceptable composition. Such a method may be practisedin vitro or in vivo.

For example, a sample of cells (e.g. from a tumour) may be grown invitro and an active compound brought into contact with said cells inconjunction with agents that have a known curative effect, and theenhancement of the curative effect of the compound on those cellsobserved.

The present invention further provides active compounds which inhibitDNA-PK activity as well as methods of methods of inhibiting DNA-PKactivity comprising contacting a cell with an effective amount of anactive compound, whether in vitro or in vivo.

The invention further provides active compounds for use in a method oftreatment of the human or animal body. Such a method may compriseadministering to such a subject a therapeutically-effective amount of anactive compound, preferably in the form of a pharmaceutical composition.

The term “treatment”, as used herein in the context of treating acondition, pertains generally to treatment and therapy, whether of ahuman or an animal (e.g. in veterinary applications), in which somedesired therapeutic effect is achieved, for example, the inhibition ofthe progress of the condition, and includes a reduction in the rate ofprogress, a halt in the rate of progress, amelioration of the condition,and cure of the condition. Treatment as a prophylactic measure (i.e.prophylaxis) is also included.

The term “therapeutically-effective amount” as used herein, pertains tothat amount of an active compound, or a material, composition or dosagefrom comprising an active compound, which is effective for producingsome desired therapeutic effect, commensurate with a reasonablebenefit/risk ratio.

Administration

The active compound or pharmaceutical composition comprising the activecompound may be administered to a subject by any convenient route ofadministration, whether systemically/peripherally or at the site ofdesired action, including but not limited to, oral (e.g. by ingestion);topical (including e.g. transdermal, intranasal, ocular, buccal, andsublingual); pulmonary (e.g. by inhalation or insufflation therapyusing, e.g. an aerosol, e.g. through mouth or nose); rectal; vaginal;parenteral, for example, by injection, including subcutaneous,intradermal, intramuscular, intravenous, intraarterial, intracardiac,intrathecal, intraspinal, intracapsular, subcapsular, intraorbital,intraperitoneal, intratracheal, subcuticular, intraarticular,subarachnoid, and intrasternal; by implant of a depot, for example,subcutaneously or intramuscularly.

The subject may be a eukaryote, an animal, a vertebrate animal, amammal, a rodent (e.g. a guinea pig, a hamster, a rat, a mouse), murine(e.g. a mouse), canine (e.g. a dog), feline (e.g. a cat), equine (e.g. ahorse), a primate, simian (e.g. a monkey or ape), a monkey (e.g.marmoset, baboon), an ape (e.g. gorilla, chimpanzee, orang-utan,gibbon), or a human.

Formulations

While it is possible for the active compound to be administered alone,it is preferable to present it as a pharmaceutical composition (e.g.formulation) comprising at least one active compound, as defined above,together with one or more pharmaceutically acceptable carriers,adjuvants, excipients, diluents, fillers, buffers, stabilisers,preservatives, lubricants, or other materials well known to thoseskilled in the art and optionally other therapeutic or prophylacticagents.

Thus, the present invention further provides pharmaceuticalcompositions, as defined above, and methods of making a pharmaceuticalcomposition comprising admixing at least one active compound, as definedabove, together with one or more pharmaceutically acceptable carriers,excipients, buffers, adjuvants, stabilisers, or other materials, asdescribed herein.

The term “pharmaceutically acceptable” as used herein pertains tocompounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgement, suitable for use in contactwith the tissues of a subject (e.g. human) without excessive toxicity,irritation, allergic response, or other problem or complication,commensurate with a reasonable benefit/risk ratio. Each carrier,excipient, etc. must also be “acceptable” in the sense of beingcompatible with the other ingredients of the formulation.

Suitable carriers, excipients, etc. can be found in standardpharmaceutical texts, for example, Remington's Pharmaceutical Sciences,18th edition, Mack Publishing Company, Easton, Pa., 1990.

The formulations may conveniently be presented in unit dosage form andmay be prepared by any methods well known in the art of pharmacy. Suchmethods include the step of bringing into association the activecompound with the carrier which constitutes one or more accessoryingredients. In general, the formulations are prepared by uniformly andintimately bringing into association the active compound with liquidcarriers or finely divided solid carriers or both, and then if necessaryshaping the product.

Formulations may be in the form of liquids, solutions, suspensions,emulsions, elixirs, syrups, tablets, losenges, granules, powders,capsules, cachets, pills, ampoules, suppositories, pessaries, ointments,gels, pastes, creams, sprays, mists, foams, lotions, oils, boluses,electuaries, or aerosols.

Formulations suitable for oral administration (e.g. by ingestion) may bepresented as discrete units such as capsules, cachets or tablets, eachcontaining a predetermined amount of the active compound; as a powder orgranules; as a solution or suspension in an aqueous or non-aqueousliquid; or as an oil-in-water liquid emulsion or a water-in-oil liquidemulsion; as a bolus; as an electuary; or as a paste.

A tablet may be made by conventional means, e.g., compression ormoulding, optionally with one or more accessory ingredients. Compressedtablets may be prepared by compressing in a suitable machine the activecompound in a free-flowing form such as a powder or granules, optionallymixed with one or more binders (e.g. povidone, gelatin, acacia,sorbitol, tragacanth, hydroxypropylmethyl cellulose); fillers ordiluents (e.g. lactose, microcrystalline cellulose, calcium hydrogenphosphate); lubricants (e.g. magnesium stearate, talc, silica);disintegrants (e.g. sodium starch glycolate, cross-linked povidone,cross-linked sodium carboxymethyl cellulose); surface-active ordispersing or wetting agents (e.g. sodium lauryl sulfate); andpreservatives (e.g. methyl p-hydroxybenzoate, propyl p-hydroxybenzoate,sorbic acid). Moulded tablets may be made by moulding in a suitablemachine a mixture of the powdered compound moistened with an inertliquid diluent. The tablets may optionally be coated or scored and maybe formulated so as to provide slow or controlled release of the activecompound therein using, for example, hydroxypropylmethyl cellulose invarying proportions to provide the desired release profile. Tablets mayoptionally be provided with an enteric coating, to provide release inparts of the gut other than the stomach.

Formulations suitable for topical administration (e.g. transdermal,intranasal, ocular, buccal, and sublingual) may be formulated as anointment, cream, suspension, lotion, powder, solution, past, gel, spray,aerosol, or oil. Alternatively, a formulation may comprise a patch or adressing such as a bandage or adhesive plaster impregnated with activecompounds and optionally one or more excipients or diluents.

Formulations suitable for topical administration in the mouth includelosenges comprising the active compound in a flavoured basis, usuallysucrose and acacia or tragacanth; pastilles comprising the activecompound in an inert basis such as gelatin and glycerin, or sucrose andacacia; and mouthwashes comprising the active compound in a suitableliquid carrier.

Formulations suitable for topical administration to the eye also includeeye drops wherein the active compound is dissolved or suspended in asuitable carrier, especially an aqueous solvent for the active compound.

Formulations suitable for nasal administration, wherein the carrier is asolid, include a coarse powder having a particle size, for example, inthe range of about 20 to about 500 microns which is administered in themanner in which snuff is taken, i.e. by rapid inhalation through thenasal passage from a container of the powder held close up to the nose.Suitable formulations wherein the carrier is a liquid for administrationas, for example, nasal spray, nasal drops, or by aerosol administrationby nebuliser, include aqueous or oily solutions of the active compound.

Formulations suitable for administration by inhalation include thosepresented as an aerosol spray from a pressurised pack, with the use of asuitable propellant, such as dichlorodifluoromethane,trichlorofluoromethane, dichoro-tetrafluoroethane, carbon dioxide, orother suitable gases.

Formulations suitable for topical administration via the skin includeointments, creams, and emulsions. When formulated in an ointment, theactive compound may optionally be employed with either a paraffinic or awater-miscible ointment base. Alternatively, the active compounds may beformulated in a cream with an oil-in-water cream base. If desired, theaqueous phase of the cream base may include, for example, at least about30% w/w of a polyhydric alcohol, i.e., an alcohol having two or morehydroxyl groups such as propylene glycol, butane-1,3-diol, mannitol,sorbitol, glycerol and polyethylene glycol and mixtures thereof. Thetopical formulations may desirably include a compound which enhancesabsorption or penetration of the active compound through the skin orother affected areas. Examples of such dermal penetration enhancersinclude dimethylsulfoxide and related analogues.

When formulated as a topical emulsion, the oily phase may optionallycomprise merely an emulsifier (otherwise known as an emulgent), or itmay comprises a mixture of at least one emulsifier with a fat or an oilor with both a fat and an oil. Preferably, a hydrophilic emulsifier isincluded together with a lipophilic emulsifier which acts as astabiliser. It is also preferred to include both an oil and a fat.Together, the emulsifier(s) with or without stabiliser(s) make up theso-called emulsifying wax, and the wax together with the oil and/or fatmake up the so-called emulsifying ointment base which forms the oilydispersed phase of the cream formulations.

Suitable emulgents and emulsion stabilisers include Tween 60, Span 80,cetostearyl alcohol, myristyl alcohol, glyceryl monostearate and sodiumlauryl sulphate. The choice of suitable oils or fats for the formulationis based on achieving the desired cosmetic properties, since thesolubility of the active compound in most oils likely to be used inpharmaceutical emulsion formulations may be very low. Thus the creamshould preferably be a non-greasy, non-staining and washable productwith suitable consistency to avoid leakage from tubes or othercontainers. Straight or branched chain, mono- or dibasic alkyl esterssuch as di-isoadipate, isocetyl stearate, propylene glycol diester ofcoconut fatty acids, isopropyl myristate, decyl oleate, isopropylpalmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branchedchain esters known as Crodamol CAP may be used, the last three beingpreferred esters. These may be used alone or in combination depending onthe properties required.

Alternatively, high melting point lipids such as white soft paraffinand/or liquid paraffin or other mineral oils can be used.

Formulations suitable for rectal administration may be presented as asuppository with a suitable base comprising, for example, cocoa butteror a salicylate.

Formulations suitable for vaginal administration may be presented aspessaries, tampons, creams, gels, pastes, foams or spray formulationscontaining in addition to the active compound, such carriers as areknown in the art to be appropriate.

Formulations suitable for parenteral administration (e.g. by injection,including cutaneous, subcutaneous, intramuscular, intravenous andintradermal), include aqueous and non-aqueous isotonic, pyrogen-free,sterile injection solutions which may contain anti-oxidants, buffers,preservatives, stabilisers, bacteriostats, and solutes which render theformulation isotonic with the blood of the intended recipient; andaqueous and non-aqueous sterile suspensions which may include suspendingagents and thickening agents, and liposomes or other microparticulatesystems which are designed to target the compound to blood components orone or more organs. Examples of suitable isotonic vehicles for use insuch formulations include Sodium Chloride Injection, Ringer's Solution,or Lactated Ringer's Injection. Typically, the concentration of theactive compound in the solution is from about 1 ng/ml to about 10 μg/ml,for example from about 10 ng/ml to about 1 μg/ml. The formulations maybe presented in unit-dose or multi-dose sealed containers, for example,ampoules and vials, and may be stored in a freeze-dried (lyophilised)condition requiring only the addition of the sterile liquid carrier, forexample water for injections, immediately prior to use. Extemporaneousinjection solutions and suspensions may be prepared from sterilepowders, granules, and tablets. Formulations may be in the form ofliposomes or other microparticulate systems which are designed to targetthe active compound to blood components or one or more organs.

Dosage

It will be appreciated that appropriate dosages of the active compounds,and compositions comprising the active compounds,

can vary from patient to patient. Determining the optimal dosage willgenerally involve the balancing of the level of therapeutic benefitagainst any risk or deleterious side effects of the treatments of thepresent invention. Theselected dosage level will depend on a variety of factors including, butnot limited to, the activity of the particularcompound, the route of administration, the time of administration, therate of excretion of the compound, the duration of the treatment, otherdrugs, compounds, and/or materials used in combination, and the age,sex, weight, condition, general health, and prior medical history of thepatient. The amount of compound and route of administration willultimately be at the discretion of the physician, although generally thedosage will be to achieve local concentrations at the site of actionwhich achieve the desired effect without causing substantial harmful ordeleterious side-effects.

Administration in vivo can be effected in one dose, continuously orintermittently (e.g. in divided doses at appropriate intervals)throughout the course of treatment. Methods of determining the mosteffective means and dosage of administration are well known to those ofskill in the art and will vary with the formulation used for therapy,the purpose of the therapy, the target cell being treated, and thesubject being treated. Single or multiple administrations can be carriedout with the dose level and pattern being selected by the treatingphysician.

In general, a suitable dose of the active compound is in the range ofabout 100 μg to about 250 mg per kilogram body weight of the subject perday. Where the active compound is a salt, an ester, prodrug, or thelike, the amount administered is calculated on the basis of the parentcompound and so the actual weight to be used is increasedproportionately.

EXAMPLES

The following are examples are provided solely to illustrate the presentinvention and are not intended to limit the scope of the invention, asdescribed herein.

Acronyms

For convenience, many chemical moieties are represented using well knownabbreviations, including but not limited to, methyl (Me), ethyl (Et),n-propyl (nPr), iso-propyl (iPr), n-butyl (nBu), tert-butyl (tBu),n-hexyl (nHex), cyclohexyl (cHex), phenyl (Ph), biphenyl (biPh), benzyl(Bn), naphthyl (naph), methoxy (MeO), ethoxy (EtO), benzoyl (Bz), andacetyl (Ac).

For convenience, many chemical compounds are represented using wellknown abbreviations, including but not limited to, methanol (MeOH),ethanol (EtOH), iso-propanol (i-PrOH), methyl ethyl ketone (MEK), etheror diethyl ether (Et₂O), acetic acid (AcOH), dichloromethane (methylenechloride, DCM), trifluoroacetic acid (TFA), dimethylformamide (DMF),tetrahydrofuran (THF), and dimethylsulfoxide (DMSO).

General Experimental Methods

Thin layer chromatography was carried out using Merck Kieselgel 60 F₂₅₄glass backed plates. The plates were visualised by the use of a UV lamp(254 nm). Silica gel 60 (particle sizes 40-63μ) supplied by E. M. Merckwas employed for flash chromatography. ¹H NMR spectra were recorded at300 MHz on a Bruker DPX-300 instrument. Chemical shifts were referencedto tetramethylsilane.

Purification and Identification of Library Samples

The samples were purified on Gilson LC units. Mobile phase A—0.1%aqueous TFA, Mobile phase B—Acetonitrile, Flow rate 6 ml/min.,Gradient—typically starting at 90% A/10% B for one minute, rising to 97%B after 15 minutes, holding there for 2 minutes, then back to thestarting conditions. Column: Jones Chromatography Genesis 4μ C18 column,10 mm×250 mm. Peak acquisition based on UV detection at 254 nm.

Mass spectra were recorded on a Finnegan LCQ instrument in positive ionmode. Mobile phase A—0.1% aqueous formic acid, Mobile phaseB—Acetonitrile, Flow rate 2 ml/min., Gradient—starting at 95% A/5% B forone minute, rising to 98% B after 5 minutes, holding there for 3minutes, then back to the starting conditions. Column: Phenomenex 5μLuna C18 column, 4.6 mm×50 mm. UV detection at 254 nm, PDA detectionscanning from 210 to 600 nm.

Mass Spectra of Other Compounds

Mass spectra of non-library compounds and intermediates were recorded ona Micromass ZQ instrument (single quadrupole, operating in electrosprayionisation mode), using a Waters 600 HPLC pump and 2700 Autosampler.

Mobile phase A—0.1% formic acid in water, Mobile phase B—0.1% formicacid in acetonitrile, Flow rate 2.0 ml/min., Gradient: 5% B to 95% Bover 3 minutes, holding there for 3 minutes. Column: Varies, but alwaysC18 50 mm×4.6 mm (Currently Genesis 4μ, Jones Chromatogrpahy). PDAdetection: Waters 996, scan range 210-400 nm.

SYNTHESIS OF KEY INTERMEDIATES (a)Morpholin-4-yl-8-(1′-nitrodibenzothiophen-4′-yl)chromen-4-one (viii)

Dibenzothiophen-4-ol (i)

To a cooled (−78° C.) solution of dibenzothiophene (20.8 g, 113 mmol) inanhydrous THF (400 ml) was added tert-butyl lithium (1.7 M in pentane;100 ml, 170 mmol). The reaction mixture was stirred at −78° C. for 1hour and then allowed to warm to room temperature and stirred like thisfor 16 hours. The mixture was then cooled to 0° C. and ethylmagnesiumbromide (1M in THF; 170 ml, 170 mmol) added to the amber reactionmixture in a slow stream via cannula. The reaction was again allowed toroom temperature whereupon it was stirred like this for 30 minutes. Areflux condenser was attached to the reaction vessel before oxygen wasbubbled through the solution for 40 minutes. The mixture was thenstirred for a further 1 hour before carefully pouring onto crushed iceand acidifying to pH 3 with concentrated HCl. The mixture was thenextracted using ethyl acetate (3×80 ml). The organic extracts were thentreated with 3M sodium hydroxide solution until pH 10 was attained. Thebasic, aqueous layer was separated, acidified to pH 3 with 2M HCl whichcaused an oily solid to precipitate. This was dissolved in diethylether(150 ml), dried using MgSO₄, filtered and concentrated in vacuo and thenrecrystallised from ethanol:water (1:1) (250 ml) to give a buff colouredsolid that corresponded to the title compound (21.6 g, 96%) and requiredno further purification. m/z (LC-MS, ESP), RT=3.64 min, (M+H)=201.1

4-Methoxy-dibenzothiophene (ii)

To a solution of dibenzothiophen-4-ol (i)(14.2 g, 71.0 mmol) in acetone(500 ml) was added powdered potassium carbonate (14.72 g, 106.5 mmol)and methyl iodide (4.43 ml, 71 mmol). The mixture was heated to refluxand stirred like this for 16 hours. The mixture was then cooled andfiltered through a Celite™ pad. The resulting filtrant was concentratedin vacuo to give an oily residue that was diluted in dichloromethane(100 ml) and washed with 1M NaOH and saturated brine solution. Theorganic layer was dried using MgSO₄, filtered and concentrated in vacuoto give a buff coloured solid that corresponded to the title compoundand was used without any further purification.(15.2 g, 100%) m/z (LC-MS,ESP), RT=4.22 min, (M+H)=215.1

4-Methoxy-1-nitro-dibenzothiophene (iii)

4-Methoxy-dibenzothiophene (ii)(4.3 g, 20.0 mmol) was dissolved inglacial acetic acid (60 ml) and to this solution was added fuming nitricacid (3.37 ml) in a dropwise fashion ensuring that the temperature ofthe mixture did not rise above 25° C. The yellow suspension was stirredfor a further 45 minutes before being poured carefully into water (200ml) and stirred for 15 minutes. The yellow solid was removed byfiltration and washed thoroughly with copious amounts of water and thenhexanes. The residue thus obtained was then dried in a vacuum oven togive the title compound as a yellow solid which was used without anyfurther purification. (5.19 g, 97%) m/z (LC-MS, ESP), RT=4.15 min,(M+H)=260.1

1-Nitro-dibenzothiophen-4-ol (iv)

Solid pyridine hydrochloride (1 kg, 8.7 mol) was added to4-methoxy-1-nitro-dibenzothiophene (iii)(35.44 g, 187 mmol) and thereaction mixed well before heating to 165° C. with continuous stirring.The mixture was maintained like this for 8 hrs, cooled, diluted withwater (500 ml) and extracted into dichloromethane (3×200 ml). 3M sodiumhydroxide solution was added to the organic extract until a dark solidprecipitated from the solution. The filtrate was removed and the liquoracidified to pH1 using concentrated HCl. The resulting bright yellowsolid that formed on acidification was then removed by filtration,washed with water and dried to give the title compound that was suitablypure to be used without any further purification. (35.44 g, 77%) m/z(LC-MS, ESP), RT=3.69 min, (M+H)=246.2, (M−H)=244.1

Trifluoro-methanesulfonic acid 1-nitro-dibenzothiophen-4-yl ester (v)

To a cooled (−5° C.) suspension of 1-nitro-dibenzothiophen-4-ol(iv)(5.37 g, 22.0 mmol) in dichloromethane (75 ml) was addedtriethylamine (9.20 ml, 66.00 mmol) which caused the suspension tosolublise completely. To this mixture was then addedtrifluoromethanesulfonic anhydride (5.85 ml, 33.00 mmol) in a dropwisefashion via syringe. The mixture was stirred at this temperature for 1hour and then poured onto crushed ice. The ice was allowed to melt andthe mixture extracted using CH₂Cl₂ (3×20 ml). The combined organiclayers were then dried (MgSO₄), filtered and concentrated in vacuo togive a mild amber oil that was eluted though a pad of silica (neatCH₂Cl₂) to give the title compound in a suitably pure form to be usedwithout any further purification. (8.30 g, 99%) %) m/z (LC-MS, ESP),RT=4.40 min, did not ionize.

Morpholin-4-yl-8-(1′-nitrodibenzothiophen-4′-yl)chromen-4-one (viii)

A clean, dry flask was charged with trifluoro-methanesulfonic acid1-nitro-dibenzothiophen-4-yl ester (v) (250 mg, 0.66 mmol),bis(pinacolato)diboron (185 mg, 0.73 mmol), potassium acetate (390 mg,3.98 mmol), PdCl₂(dppf) (27 mg, 0.033 mmol), and dppf (19 mg, 0.033mmol) under argon. The flask was evacuated under vacuum and flushed withargon three times. Dioxane (20 ml) was added and the reaction mixturewas stirred at 90° C. for 12 hours. The reaction mixture was dilutedwith DCM (100 ml) and organic layer was washed successively with water(3×30 ml), brine (1×30 ml), dried (Na₂SO₄) and the solvent wasevaporated in vacuo to furnish the nitroboronate ester (vi) which wasused without further purification. A mixture of vi (280 mg, 0.79 mmol),chromenone-8-triflate (vii) (298 mg, 0.79 mmol), PdCl₂(dppf) (19.3 mg,0.024 mmol), and Cs₂CO₃ (770 mg, 2.36 mmol) was flushed three times withargon, and THF (20 ml) was added. The reaction mixture was stirred underreflux for 12 hours. The solvents was removed in vacuo and the residuewas dissolved in DCM, (100 ml) washed with water (2×30 ml), brine (1×30ml), dried (Na₂SO₄) and the solvent was evaporated in vacuo to furnishthe title compound (viii). The crude product was purified by columnchromatography using 2-5% methanol in DCM.

m.p=179° C.; R_(f)=0.28 (DCM/MeOH 95/5); LC-MS ES⁺460. IR (film): 1681,1619, 1559, 1404 cm⁻¹; UV:λmax=240 nm. ¹H NMR (300 MHz, CDCl₃): δ 8.27(dd, J=7.8; 1.6 Hz, 1H); 8.09 (d, J=7.5 Hz, 1H); 7.83 (d, J=7.9 Hz, 1H);7.78 (d, J=7.1 Hz, 1H); 7.66 (dd, J=7.5; 1.6 Hz, 1H); 7.42-7.52 (m, 4H);5.45 (s, 1H); 3.40-3.47 (m, 4H); 3.00-3.03 (m, 4H). ¹³C NMR (75 MHz,CDCl₃): δ 176.9; 162.5; 150.8; 151.7; 143.4; 140.5; 135.9; 133.5; 131.6;129.0; 127.5; 127.4; 127.0; 125.8; 125.6; 125.4; 124.1; 123.1; 120.8;87.6; 66.0; 44.9.

(b) 8-(1′-Aminodibenzothiophen-4′-yl)-2-morpholin-4-yl-chromen-4-one(ix)

To a solution of the nitrodibenzothiophene derivative (viii) (810 mg,1.77 mmol) in acetic acid (30 ml) was added zinc powder (1.16 g, 17.70mmol) and the reaction mixture was stirred at room temperatureovernight. The reaction mixture was filtered through celite, washedsuccessively with methanol (4×50 ml) and DCM (2×50 ml) and the combinedfiltrates were evaporated under reduced pressure. The residual solid wasstirred with water (100 ml) and aqueous ammonia (25 ml) was added. Theresultant precipitated solid was collected by filtration, and purifiedby chromatography on silica employing 2-5% methanol in DCM as eluent.

R_(f)=0.28 (DCM/MeOH 95/5); IR (film): 3326, 3211, 2962, 2902, 2851,1729, 1615, 1555. ¹H NMR (300 MHz, CDCl₃): δ 8.14-8.20 (m, 2H); 7.74(dd, J=7.7; 1.1 Hz, 1H); 7.67 (dd, J=7.4; 1.7 Hz, 1H); 7.34-7.49 (m,4H); 7.22 (d, J=7.8 Hz, 1H); 6.82 (d, J=7.8 Hz, 1H); 5.48 (s, 1H, ═CH);4.55 (br, —NH, 2H); 3.42-3.46 (m, 4H); 3.03-3.06 (m, 4H). ¹³C NMR (75MHz, CDCl₃): δ 177.6; 162.5; 151.7; 144.2; 141.6; 138.9; 135.8; 134.1;132.8; 129.1; 128.9; 126.0; 125.7; 125.3; 125.1; 125.0; 123.8; 123.7;123.1; 123.0; 122.0; 113.1; 87.18; 66.4; 45.0.

(c)2-Chloro-N-[4-(2-morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yl]-acetamide(A)

To a solution of the aminodibenzothiophene derivative (ix, 1 mol.equiv.) in dry DMA (12 ml) was added triethylamine (2.2 mol. equiv.) andchloroacetyl chloride (1.1 mol. equiv.), and the reaction mixture wasstirred at room temperature for 4 hours.

(d)3-Bromo-N-[4-(2-morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yl]-propionamide(B)

To a solution of the aminodibenzothiophene derivative (ix; 1 mol.equiv.) in dry DMA, was added triethylamine (2.2 mol. equiv.) and3-bromopropionyl chloride (1.1 mol. equiv.), and the reaction mixturewas stirred at room temperature for 4 hours.

(e) 8-(1-Hydroxy-dibenzothiophen-4-yl)-2-morpholin-4-yl-chromen-4-one(x)

The aminodibenzothiophene derivative (ix) (1 mmol) was suspended inethanol (40 ml) and HBF₄ (15 mmol) was added dropwise at roomtemperature. After stirring for 15 minutes the reaction mixture became aclear solution, which was cooled to 0° C. and t-butylnitrite (2 mmol)was added. After 30 minutes the reaction mixture was diluted with ether(80 ml). The precipitated solid was filtered, washed with ether (2×20ml) and dried. This solid was added to a solution of cupric nitrate (300mmol) in 1 L of water containing cuprous oxide (1 mmol) and stirred for1 hour at room temperature. The aqueous solution was filtered to affordthe product as brown solid, which was purified by column chromatographyon silica using 2-5% methanol/DCM.

(f)8-[1-(2-Bromo-ethoxy)-dibenzothiophen-4-yl]-2-morpholin-4-yl-chromen-4-one(c)

To a solution of the 1-hydroxydibenzothiophene (x; 1 mol. equiv.) in dryDMF (20 ml) was added potassium carbonate (1.1 mol. equiv.) anddibromoethane (1.1 mol. equiv.), and the reaction mixture was stirred atroom temperature for 12 hours.

(g) Sodium[4-(2-Morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yloxy]-acetate(D)

The hydroxyl compound (x) was suspended in dry DMF, potassium carbonatewas added followed by methyl bromoacetate, and the reaction mixture wasstirred at 60° C. overnight. After completion of the reaction, thereaction mixture was poured into water and extracted with ethyl acetate.The organic layer was washed with water, brine, dried and concentratedto give the methyl ester as a yellow solid. The progress of the reactionwas monitored by HPLC and LC-MS. The ester was dissolved in methanol andaqueous NaOH was added. The reaction mixture was stirred at 60° C. for 1hour, when HPLC and LC-MS showed the absence of the methyl ester. Thereaction mixture was evaporated to dryness in vacuo to afford the sodiumsalt (D).

Example 1

Aliquots (0.5 ml) of2-Chloro-N-[4-(2-morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yl]-acetamide(A) were added to each of the vials containing the various amines forthe synthesis. The reaction mixtures were stirred in parallel at roomtemperature for 12 hours, diluted with a minimum volume of methanol, andthe resulting compounds were then purified.

Compound R M/z Rt (min) Purity (%) 1

556.4 3.5 95 2

554.5 3.38 95 3

555.4 3.25 95 4

569.4 3.28 95 5

574.4 3.2 95 6

602.4 3.66 90 7

530.4 3.21 95 8

529.4 2.99 95 9

583.5 3.26 90 10

568.5 3.49 95 11

606.4 3.57 95 12

542.5 3.38 95 13

486.4 3.19 95 14

599.4 3.16 95 15

570.4 3.36 95 16

597.5 3.11 95 17

571.4 3.28 95 18

584.5 3.65 90 19

605.5 3.48 85 20

598.5 3.23 90 21

597.5 3 95 22

544.4 3.32 95 23

597.6 3.39 95 24

613.6 3.34 85 25

643.6 3.25 95 26

583.6 3.29 95 27

632.6 3.44 95 28

649.6 4.06 90 29

654.5 3.39 90 30

626.4 3.02 95 31

597.4 3.23 95 32

599.4 3.24 95 33

613.4 3.22 95 34

613.4 2.98 95 35

569.4 3.18 95 36

514.4 3.28 95 37

577.4 3.22 90 38

597.4 3.36 90 39

570.4 3.68 95

Representative Analytical Data

Compound 1: ¹H NMR (300 MHz, CDCl₃): δ 10.27 (1H, s, —NH), 8.44 (1H, m,Ar), 8.29 (1H, d, J=7.85 Hz, Ar), 8.04 (1H, d, J=8.04 Hz, Ar), 7.86 (2H,m, Ar), 7.55 (4H, m, Ar), 6.59 (1H, s, ═CH—), 4.01 (4H, m, —NCH₂CH₂—),3.82 (2H, s, —NCH₂), 3.53 (4H, m, —NCH₂CH₂—), 3.26 (4H, m, —NCH₂CH₂—),3.18 (4H, m, —NCH₂CH₂—). M.p.: 165° C.

Compound 2: ¹H NMR (300 MHz, CDCl₃): δ 10.80 (1H, s, —NH), 8.26 (1H, m,Ar), 8.19 (1H, dd, J=1.6 Hz, Ar), 7.70 (2H, m, Ar), 7.48 (2H, m, Ar),7.38 (3H, m, Ar), 6.15 (1H, s, ═CH—), 4.10 (2H, s, —NCH₂), 3.42 (6H, m,—NCH₂CH₂—), 3.09 (7H, m, —NCH₂CH₂—), 1.95 (5H, m, —CH₂CH₂—). M.p.: 188°C.

Compound 17(oil): ¹H NMR (300 MHz, CDCl₃): δ 10.15 (1H, s, —NH), 8.22(2H, t, J=7.93 Hz, Ar), 7.74 (2H, t, J=7.64 Hz, Ar), 7.58 (1H, d, J=7.95Hz, Ar), 7.50 (1H, d, J=7.67 Hz, Ar), 7.36 (3H, m, Ar), 6.58 (1H, s,═CH—), 3.53 (2H, s, —NCH₂), 3.45 (4H, m, —NCH₂CH₂—), 3.20 (6H, m,—NCH₂CH₂—), 3.03 (2H, m, —NCH₂), 2.91 (6H, s, —NCH₃), 2.56 (3H, s,—NCH₃).

Compound 18: ¹H NMR (300 MHz, CDCl₃): δ 10.26 (1H, s, —NH), 8.32 (1H, d,J=6.42 Hz, Ar), 8.20, (1H, d, J=6.36 Hz, Ar), 7.90 (1H, m, Ar), 7.74(2H, m, Ar), 7.47 (4H, m, Ar), 6.40 (1H, s, ═CH—), 3.96 (2H, m, —NCH₂),3.77 (2H, s, —OCH₂), 3.44 (4H, m, —NCH₂CH₂—), 3.27 (2H, d, J=11.57 Hz,—NCH₂), 3.15 (4H, s, —NCH₂CH₂—), 2.50 (2H, m, —NCH₂). M.p.: 152° C.

Compound 27: ¹H NMR (300 MHz, CDCl₃): δ 9.90 (1H, s, —NH), 8.38 (1H, m,Ar), 8.22 (3H, m, Ar), 7.77 (3H, m, Ar), 7.45 (4H, m, Ar), 6.89 (2H, m,Ar), 6.32 (1H, S, ═CH—), 3.89 (2H, bs, —NCH₂), 3.51 (4H, s, —NCH₂CH₂—),3.46 (4H, m, —NCH₂CH₂—), 3,17 (4H, m, —NCH₂CH₂—), 3.03 (4H, m,—NCH₂CH₂—). M.p.: 171° C.

Example 2

Aliquots (0.5 ml) of3-Bromo-N-[4-(2-morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yl]-propionamide(B) were added to each of the vials containing the various amines forthe synthesis. The reaction mixtures were stirred in parallel at roomtemperature for 12 hours, diluted with a minimum volume of methanol, andthe resulting compounds were then purified.

Compound R M/z Rt (min) Purity (%) 40

570.5 3.29 95 41

568.4 3.39 95 42

569.4 3.15 95 43

583.4 3.22 95 44

588.4 3.23 95 45

544.4 3.23 95 46

543.4 2.98 95 47

597.4 3.03 85 48

582.5 3.44 95 49

620.5 3.58 95 50

556.5 3.38 95 51

500.3 3.26 95 52

613.5 3.13 95 53

584.4 3.43 95 54

611.5 3.03 95 55

585.4 3.08 95 56

598.4 3.38 90 57

619.4 3.33 95 58

612.4 3.25 95 59

611.4 3.01 95 60

558.3 3.35 90 61

611.4 3.25 90 62

627.4 3.24 95 63

657.4 3.2 95 64

597.4 3.23 95 65

646.4 3.33 95 66

663.4 3.73 95 67

647.5 3.45 85 68

668.5 3.37 85 69

640.1 3.03 90 70

611.4 3.02 85 71

613.5 3.18 85 72

627.5 2.99 95 73

627.5 3.02 95 74

591.3 3.13 95 75

611.3 3.27 95 76

584.5 3.73 95

Representative Analytical Data

Compound 48: ¹H NMR (300 MHz, CDCl₃): δ 9.32 (1H, s, —NH), 8.22 (2H, m,Ar), 7.73 (2H, m, Ar), 7.58 (1H, d, J=7.82 Hz, Ar), 7.40 (4H, m, Ar),6.12 (1H, s, ═CH—) 3.54 (4H, m), 3.44 (4H, m), 3.29 (2H, m), 3.11 (6H,m), 2.37 (bs), 1.76 (m).

Compound 53: ¹H NMR (300 MHz, CDCl₃): δ 9.19 (1h, s, —NH), 8.20 (2H, m,Ar), 7.69 (2H, m, Ar), 7.53 (1H, m, Ar), 7.41 (1H, m, Ar), 6.00 (1H, s,═CH—), 4.16 (1H, m), 3.68 (2H, m), 3.42 (8H, m), 3.06 (4H, m), 2.62 (8H,m). M.p.: 148° C.

Example 3

Aliquots (0.5 ml) of8-[1-(2-bromo-ethoxy)-dibenzothiophen-4-yl]-2-morpholin-4-yl-chromen-4-one(C) were added to each of the vials containing the various amines forthe synthesis. The reaction mixtures were stirred in parallel at roomtemperature for 12 hours, diluted with a minimum volume of methanol, andthe resulting compounds were then purified.

Rt Purity Compound R M/z (min) (%) 77

543.6 3.55 90 78

571.4 3.72 95 79

541.4 3.67 95 80

556.4 3.65 95 81

586.4 3.32 90 82

575.4 3.52 95 83

584.5 3.65 95 84

584.5 3.46 95 85

564.4 3.38 90 86

550.4 3.56 95 87

529.4 3.65 95 88

501.4 3.5 95 89

558.3 3.39 95 90

570.4 3.29 95 91

530.4 3.38 90

Representative Analytical Data

Compound 78: ¹H NMR (300 MHz, CDCl₃): δ 8.84 (1H, m, Ar0, 8.28 (1H, d,J=7.85 Hz, Ar), 7.76 (2H, m, Ar), 7.50 (3H, m, Ar), 7.35 (1H, d, J=8.22Hz, Ar), 7.11 (1H, d, J=8.45 Hz, Ar), 5.95 (1H, s, ═CH), 5.07 (2H, d,J=9.50 Hz, —OCH₂), 4.47 (1H, d, —OCH(CH₃)), 3.96 (1H, d, —CH(CH₃)), 3.51(8H, m, —NCH₂), 3.16 (4H, m, —NCH₂), 1.22 (3H, d, J=6.20 Hz, —CH₃), 1.12(3H, d, J=6.24 Hz, —CH₃). M.p.: 240° C.

Compound 80: ¹H NMR (300 MHz, CDCl₃): δ 8.73 (1H, dd, J=5.12 Hz, Ar),8.01 (1H, dd, J=7.85 Hz, Ar), 7.81 (1H, dd, J=7.54 Hz, Ar), 7.73 (1H,dd, J=7.42 Hz, ar), 7.51 (1H, d, J=8.23 Hz, Ar), 7.42 (3H, m, Ar), 7.19(1H, d, J=8.35 Hz, Ar), 4.54 (2H, m, —OCH₂), 3.39 (8H, t, J=4.64 Hz,N—CH₂), 3.34 (2H, m, —N—CH₂), 3.10 (8H, t, J=4.81 Hz, N—CH₂), 2.81 (3H,s, —N—CH₃). M.p.: 100° C.

Compound 81: ¹H NMR (300 MHz, CDCl₃): δ 8.66 (1H, dd, J=9.39 Hz, Ar),7.99 (1H, dd, J=6.19 Hz, Ar), 7.79 (1H, dd, J=5.97 Hz, Ar), 7.72 (1H,dd, J=7.44 Hz, Ar), 7.51 (1H, d, J=7.46 Hz, Ar), 7.38 (3H, m, Ar), 7.22(1H, d, J=8.31 Hz, Ar), 4.76 (2H, t, J=5.58 Hz, —OCH₂), 3.79 (10H, m,—NCH₂ & —OCH₂), 3.58 (2H, m, —NCH₂), 3.38 (8H, t, J=5.06 Hz, —NCH₂),3.20 (1H, s, —NH), 3.09 (2H, t, J=4.89 Hz, —NCH₂). M.p.: 70° C.

Compound 83: ¹H NMR (300 MHz, CDCl₃): δ 8.55 (1H, d, J=6.67 Hz, Ar),7.99 (1H, dd, J=6.24 Hz, Ar), 7.72 (2H, m, Ar), 7.45 (4H, m, Ar), 6.99(1H, d, J=8.27 Hz, Ar), 6.39 (1H, s, ═CH), 4.58 (2H, m, —OCH₂), 3.54(3H, m, —CH(CH₃)₂ & —NCH₂), 3.45 (12H, m, —NCH₂), 3.17 (4H, m, —NCH₂),1.32 (6H, d, J=6.67 Hz, (CH₃)₂CH—). M.p.: 158° C.

Compound 87: ¹H NMR (300 MHz, CDCl₃): δ 8.57 (1H, m, Ar), 8.29 (1H, d,J=7.85 Hz, Ar), 7.82 (2H, m, Ar), 7.51 (4H, m, Ar), 7.12 (1H, d, J=8.23Hz, Ar), 6.59 (1H, s, ═CH), 4.85 (2H, m, —OCH₂), 3.78 (2H, m, —NCH₂),3.54 (4H, m, —OCH₂), 3.47 (4H, m, —NCH₂), 3.28 (4H, m, —NCH₂), 1.47 (6H,t, J=7.38 Hz, —CH₃). M.p.: 147° C.

Compound 88: ¹H NMR (300 MHz, CDCl₃): δ 8.68 (1H, m, Ar), 8.02 (1H, dd,J=7.83 Hz, Ar), 7.82 (1H, m, Ar), 7.76 (1H, dd, J=7.34 Hz, Ar), 7.45(1H, d, J=7.52 Hz, Ar), 7.40 (2H, m, Ar). 7.25 (1H, d, J=8.42 Hz, Ar),4.84 (2H, m, —OCH₂), 3.92 (2H, m, —NCH₂), 3.39 (8H, m, —OCH₂), 3.11 (8H,m, —NCH₂), 3.05 (6H, s, (CH₃)₂N—). M.p.: 166° C.

Example 4

Sodium[4-(2-Morpholin-4-yl-4-oxo-4H-chromen-8-yl)-dibenzothiophen-1-yloxy]-acetate(D) was dissolved in DMF, and aliquoted in 15 equal portions intoreaction tubes containing the appropriate amines. A solution of HBTU andHOBT in dry DMF was added to each tube, and the reaction mixtures werestirred at room temperature overnight. The resulting products were thenpurified.

Rt Purity Compound R M/z (min) (%) 92

585.4 4.67 95 93

555.4 4.78 95 94

570.4 3.49 95 95

589.4 4.04 95 96

598.5 3.6 95 97

598.5 3.99 95 98

578.5 3.6 95 99

572.4 3.54 95 100

584.5 3.53 95 101

544.4 3.75 95 102

488.4 4.26 95

Example 58-(1′-Acetylaminodibenzothiophen-4′-yl)-2-morpholin-4-yl-chromen-4-one(103)

(a) 4-Trifluoromethanesulfonyl-dibenzothiophen-1-ylamine (xi)

A solution of glacial acetic acid (80 mL) containing Zn powder (1.17 g,17.96 mmol) and compound trifluoro-methanesulfonic acid1-nitro-dibenzothiophen-4-yl ester (v)(1.13 g, 2.99 mmol, 1 equiv.) wasstirred at room temperature overnight. Upon completion the solution wasfiltered through a Celite™ pad. The Celite™ cake was then washed withdichloromethane and the organic phase was concentrated in vacuo. Thecrude product was purified by flash chromatography (SiO₂) (DCM/petrol4/6 then 6/4) leading to the desired compound as a white solid (0.84 g,80% yield).

m.p=108° C.; R_(f)=0.34 (DCM/petrol 6/4); LC-MS m/z 348 [M+1]¹H NMR (300MHz, CDCl₃): δ 8.06-8.09 (m, 1H); 7.77-7.81 (m, 1H); 7.36-7.44 (m, 2H);7.14 (d, J=8.6 Hz, 1H); 6.63 (d, J=8.6 Hz, 1H); 3.94 (s, NH₂). ¹³C NMR(75 MHz, CDCl₃):δ 143.9; 138.8; 136.9; 135.4; 134.1; 126.6; 125.4;124.8; 123.6; 123.3; 119.7; 119.4 (q, J=317 Hz, CF₃); 113.0.

(b) 1-acetylaminodibenzothiophene triflate (xii)

To a solution of the aminodibenzothiophene triflate (200 mg, 0.58 mmol)in pyridine (4.0 ml), was added acetic anhydride (0.29 ml, 2.88 mmol)dropwise. The reaction mixture was stirred at room temperature for 12hours, diluted with water (20 ml), and extracted with ethyl acetate(3×10 ml). The combined organic layers were washed successively withwater (2×20 ml), saturated aqueous sodium bicarbonate solution (1×20 ml)and brine (1×20 ml), dried (Na₂SO₄) and evaporated in vacuo. Theresidual solid was triturated with petrol to give the title compound(xii).

LC/MS (in MeOH): Tr=3.15 min. ¹H NMR (300 MHz, CDCl₃): δ 9.51 (1H, s,NH), 8.48 (1H, d, J=8.1 Hz), 8.25 (1H, d, J=7.42 Hz), 7.71-7.53 (4H, m),2.33 (3H, s, —CH₃). ¹³C NMR (75 MHz, CDCl₃): δ 139.81, 135.34, 129.05,126.56, 124.19, 120.00, 24.09.

(c) 2-morpholin-4-yl-8-(4,4,5,5,-tetramethyl-[1, 3, 2°dioxaborolan-4-yl)-4a,8a-dihydro-chromen-4-one (xiii)

A suspension of2-morpholin-4-yl-8-trifluoromethanesulfonyl-chromen-4-one (vii)(1.0 g,2.637 mmol), bis(pinacolato)diboron (0.803 g, 3.165 mmol) and potassiumacetate (0.776 g, 7.911 mmol), 1,4-dioxane (30 mL) was degassed bybubbling nitrogen through the solution while sonicating for 15 min. Tothe reaction mixture was than added(1,1′-Bis(diphenylphosphino)ferrocene-dichloropalladium(II), (107 mg,0.132 mmol) and 1,1-Bis(diphenylphosphino)ferrocene (73 mg, 0.132 mmol).The reaction was heated at 90° C. under N₂ for 16 hours. On completionthe solution was diluted in ether and the organic layer was washed witha saturated NaCl solution, dried over MgSO₄ and concentrated in vacuumto give the title compound as a black solid (0.80 g, 85% yield) whichwas used without purification. LC-MS m/z 358 [M+1]; ¹H NMR (300 MHz,CDCl₃): δ 8.20 (d, J=6.3 Hz, 1H); 7.94 (d, J=7.2 Hz, 1H); 7.27 (t, J=7.5Hz, 1H); 5.51 (s, 3H); 3.74-3.78 (m, 4H); 3.61-3.64 (m, 4H): 1.19 (s,12H); ¹³C NMR (75 MHz, CDCl₃): δ 178.0; 162.0; 158.1; 140.6; 129.6;124.7; 86.8; 84.3; 83.5; 66.5; 45.1; 25.4; 24.9.

(d)8-(1′-Acetylaminodibenzothiophen-4′-yl)-2-morpholin-4-yl-chromen-4-one(103)

A mixture of xii (100 mg, 0.26 mmol), xiii (100 mg, 0.28 mmol),Pd(PPh₃)₄ (14.5 mg, 0.013 mmol) and potassium carbonate (106 mg, 0.768mmol) was flushed with argon three times in vacuo, and dioxane (15 ml)was added. The reaction mixture was stirred at 85° C. for 12 hours. Themixture was diluted with DCM (50 ml) and the organic layer was washedsuccessively with water (2×20 ml), brine (1×20 ml), dried (Na₂SO₄) andthe solvent was evaporated in vacuo. The residual solid was purified bychromatography on silica, employing 5% methanol in DCM as eluent, toafford the title compound (103).

Rt=3.73 min; m/z=471.4; purity=95%

Biological Examples DNA-PK Inhibition

In order to assess the inhibitory action of the compounds against DNA-PKin vitro, the following assay was used to determine IC₅₀ values.

Mammalian DNA-PK (500 ng/ml) was isolated from HeLa cell nuclear extract(Gell, D. and Jackson S. P., Nucleic Acids Res. 27:3494-3502 (1999))following chromatography utilising Q-sepharose, S-sepharose and Heparinagarose. DNA-PK (250 ng) activity was measured at 30° C., in a finalvolume of 40 μl, in buffer containing 25 mM Hepes, pH7.4, 12.5 mM MgCl₂,50 mM KCl, 1 mM DTT, 10% Glycerol, 0.1% NP-40 and 1 mg of the substrateGST-p53N66 (the amino terminal 66 amino acid residues of human wild typep53 fused to glutathione S-transferase) in polypropylene 96 well plates.To the assay mix, varying concentrations of inhibitor (in DMSO at afinal concentration of 1%) were added. After 10 minutes of incubation,ATP was added to give a final concentration of 50 μM along with a 30merdouble stranded DNA oligonucleotide (final concentration of 0.5 ng/ml)to initiate the reaction. After 1 hour with shaking, 150 μl of phosphatebuffered saline (PBS) was added to the reaction and 5 μl thentransferred to a 96 well opaque white plate containing 45 μl of PBS perwell where the GSTp53N66 substrate was allowed to bind to the wells for1 hour. To detect the phosphorylation event on the serine 15 residue ofp53 elicited by DNA-PK a p53 phosphoserine-15 antibody (Cell SignalingTechnology) was used in a basic ELISA procedure. An anti-rabbit HRPconjugated secondary antibody (Pierce) was then employed in the ELISAbefore the addition of chemiluminescence reagent (NEN Renaissance) todetect the signal as measured by chemiluminescent counting via aTopCount NXT (Packard).

The enzyme activity for each compound is then calculated using thefollowing equation:

${\% \mspace{14mu} {Inhibition}} = {100 - \left( \frac{\left( {{cpm}\mspace{14mu} {of}\mspace{14mu} {unknown}\text{-}{mean}{\mspace{11mu} \;}{negative}\mspace{14mu} {cpm}} \right) \times 100}{\left( {{mean}\mspace{14mu} {positive}\mspace{14mu} {cpm}\text{-}{mean}\mspace{14mu} {negative}\mspace{14mu} {cpm}} \right.} \right)}$

The results are discussed below as IC₅₀ values (the concentration atwhich 50% of the enzyme activity is inhibited). These are determinedover a range of different concentrations, normally from 10 μM down to0.01 μM. Such IC₅₀ values are used as comparative values to identifyincreased compound potencies.

Survival Enhancement Ratio

The Survival Enhancement Ratio (SER) is a ratio of the enhancement ofcell kill elicited by the DNA-PK inhibitor after 2 Grays of irradiationcompared to unirradiated control cells. DNA-PK inhibitors were used at afixed concentration of 100 nM. Radiation was delivered by a Faxitron43855D machine at a dose rate of 1 Gy pre minute The SER at 2 Grayirradiation was calculated from the formula:

${SER} = {\frac{{Cell}\mspace{14mu} {survival}\mspace{14mu} {in}\mspace{14mu} {presence}\mspace{14mu} {of}\mspace{11mu} D\; N\; A\text{-}P\; K\mspace{14mu} {inhibitor}}{{Cell}\mspace{14mu} {survival}\mspace{14mu} {of}\mspace{14mu} {control}\mspace{14mu} {cells}} \times \frac{{Cell}\mspace{14mu} {survival}\mspace{14mu} {after}\mspace{14mu} I\; R}{{Cell}\mspace{14mu} {survival}\mspace{14mu} {after}\mspace{14mu} I\; R\mspace{14mu} {in}\mspace{14mu} {presence}\mspace{14mu} {of}\mspace{14mu} D\; N\; A\text{-}P\; K\mspace{14mu} {inhibitor}}}$

The degree of cell killing was monitored by a standard clonogenicsurvival assay. Briefly, tissue culture treated 6-well plates wereseeded with HeLa cells at an appropriate concentration to give 100-200colonies per well and returned to the incubator in order to allow thecells to attach. Four hours later, compound or vehicle control was addedto the cells. The cells were then incubated for 1 hour in the presenceof inhibitor prior to irradiation at 2 Gray using a Faxitron 43855Dcabinet X-ray machine. The cells were then incubated for a further 16hours before the media was replaced with fresh media in the absence ofDNA-PK inhibitor. After 8 days, colonies formed were fixed and stainedwith Giemsa (Sigma, Poole, UK) and scored using an automated colonycounter (Oxford Optronics Ltd, Oxford, UK). The data was calculated asdescribed above.

All the compounds showed activity in DNA-PK inhibition, exhibiting anIC₅₀ of less than about 100 nM.

Compounds which exhibited particular efficacy in DNA-PK inhibition,having an IC₅₀ of less than about 10 nM include 5, 18, 23, 24, 25, 26,29, 32, 51, 53, 60, 81, 82, 83, 84, 85, 86, 88, 90, 91, 95.

All the compounds showed an SER of 1 or more. The following compoundshad an SER of 2 or more: 1, 4, 13, 24, 26, 32, 34, 38, 40, 41, 48, 53,56, 80, 82, 84, 88, 89.

1. A compound of formula I:

and isomers, salts, solvates, chemically protected forms, and prodrugsthereof, wherein: R¹ and R² are independently selected from hydrogen, anoptionally substituted C₁₋₇ alkyl group, C₃₋₂₀ heterocyclyl group, orC₅₋₂₀ aryl group, or may together form, along with the nitrogen atom towhich they are attached, an optionally substituted heterocyclic ringhaving from 4 to 8 ring atoms; Q is —NH—C(═O)— or —O—; Y is anoptionally substituted C₁₋₅ alkylene group; X is SR³, wherein, R³ isselected from hydrogen, optionally substituted C₁₋₇ alkyl, C₅₋₂₀ aryl,or C₃₋₂₀ heterocyclyl groups; if Q is —O—, X is additionally selectedfrom NR⁴R⁵ and —C(═O)—NR⁶R⁷, wherein R⁴ and R⁵ are independentlyselected from hydrogen, optionally substituted C₁₋₇ alkyl, C₅₋₂₀ aryl,or C₃₋₂₀ heterocyclyl groups, or R⁴ and R⁵ may together form, along withthe nitrogen atom to which they are attached, an optionally substitutedheterocyclic ring having from 4 to 8 ring atoms, and R⁶ and R⁷ areindependently selected from hydrogen, optionally substituted C₁₋₇ alkyl,C₅₋₂₀ aryl, or C₃₋₂₀ heterocyclyl groups, or R⁶ and R⁷ may togetherform, along with the nitrogen atom to which they are attached, anoptionally substituted heterocyclic ring having from 4 to 8 ring atoms;and if Q is —NH—C(═O)—, —Y—X may additionally be selected from C₁₋₇alkyl.
 2. A compound according to claim 1, wherein Q is —NH—C(═O)— or—O—
 3. A compound according to claim 2, wherein X is NR⁴R⁵.
 4. Acompound according to claim 3, wherein Y is an optionally substitutedC₁₋₃ alkylene group.
 5. A compound according to claim 4, wherein Y is aC₁₋₂ alkylene group.
 6. A compound according to claim 1, wherein R⁴ andR⁵ are either independently selected from H and optionally substitutedoptionally substituted C₁₋₇ alkyl or R⁴ and R⁵ form, together with thenitrogen atom to which they are attached, an optionally substitutednitrogen containing heterocylic ring having from 4 to 8 ring atoms.
 7. Acompound according to claim 1 or formula II:

wherein: R¹, R² and Q are as defined for formula I; n is 1 to 7; and R⁸is selected from hydrogen, optionally substituted C₁₋₇ alkyl, optionallysubstituted C₅₋₂₀ aryl, and acyl.
 8. A compound according to claim 1,wherein R¹ and R² form, along with the nitrogen atom to which they areattached, a heterocyclic ring having from 4 to 8 atoms.
 9. A compoundaccording to claim 8, wherein R¹ and R² form, along with the nitrogenatom to which they are attached, a heterocyclic ring having 6 ringatoms.
 10. A compound according to claim 8, wherein R¹ and R² form,along with the nitrogen atom to which they are attached, morpholino orthiomorpholino.
 11. A pharmaceutical composition comprising a compoundaccording claim 1, a pharmaceutically acceptable carrier or diluent. 12.A method of treatment of a disease ameliorated by the inhibition ofDNA-PK, comprising administering to a subject in need of treatment atherapeutically effective amount of a compound according to claim
 1. 13.The method according to claim 12, wherein the disease ameliorated by theinhibition of DNA-PK is a retroviral mediated disease.
 14. A method oftreatment of cancer, comprising administering to a subject in need oftreatment a therapeutically effective amount of a compound according toclaim 1 simultaneously or sequentially in combination with ionisingradiation or a chemotherapeutic agent.